TY - JOUR A1 - Seibold, Götz A1 - Lorenzana, José T1 - The unrestricted Gutzwiller+RPA approach and its application to stripes in cuprates Y1 - 2005 ER - TY - JOUR A1 - Lorenzana, José A1 - Seibold, Götz T1 - Dynamical and statical properties of stripes in cuprates Y1 - 2004 ER - TY - JOUR A1 - Seibold, Götz A1 - Lorenzana, José T1 - Time-dependent Gutzwiller approximation for the Hubbard Model Y1 - 2001 ER - TY - JOUR A1 - Schmeißer, Dieter A1 - Seibold, Götz A1 - Reif, Jürgen T1 - Nano-scaled Dielectric Barriers (NanoDieB) for CMOS compatible Si-technologies JF - Forum der Forschung KW - nano-scaled KW - dielectric KW - CMOS Y1 - 2006 SN - 0947-6989 IS - 19 SP - 131 EP - 136 ER - TY - GEN A1 - Seibold, Götz T1 - On the Evaluation of Higher-Harmonic-Current Responses for High-Field Spectroscopies in Disordered Superconductors T2 - Condensed Matter N2 - We discuss a formalism that allows for the calculation of a higher-harmonic-current response to a strong applied electric field for disordered superconducting systems described on the basis of tight-binding models with on- and/or intersite interactions. The theory is based on an expansion of the density matrix in powers of the field amplitudes, where we solve the equation of motion for the individual components. This allows the evaluation of higher-order response functions on significantly larger lattices than one can achieve with a previously used approach, which is based on a direct temporal integration of the equation of motion for the complete density matrix. In the case of small lattices, where both methods can be applied by including also the contribution of collective modes, we demonstrate the agreement of the corresponding results. KW - superconductivity KW - third-harmonic generation KW - disorder Y1 - 2023 UR - https://www.mdpi.com/2410-3896/8/4/95 U6 - https://doi.org/10.3390/condmat8040095 SN - 2410-3896 VL - 8 IS - 4 SP - 1 EP - 16 ER - TY - RPRT A1 - Noell, M. A1 - Seibold, Götz A1 - Krebs, Andreas T1 - Excitations in disordered superconductors: Inclusion of long-range Coulomb interactions Y1 - 2019 UR - https://www.hlrn.de/HLRN-Report-2019.pdf SN - 978-3-00-063360-7 SP - 269 PB - HLRN CY - Berlin ER - TY - GEN A1 - Hokamp, Sascha A1 - Seibold, Götz T1 - Tax Compliance and Public Goods Provision An Agent-based Econophysics Approach T2 - Central European Journal of Economic Modelling and Econometrics N2 - We calculate the dynamics of tax evasion within a multi-agent econophysics model which is adopted from the theory of magnetism and previously has been shown to capture the main characteristics from agent-based based models which build on the standard Allingham and Sandmo approach. In particular, we implement a feedback of public goods provision on the decision-making of selfish agents which aim to pursue their self interest. Our results imply that such a feedback enhances the moral attitude of selfish agents thus reducing the percentage of tax evasion. Two parameters govern the behavior of selfish agents, (i) the rate of adaption to changes in public goods provision and (ii) the threshold of perception of public goods provision. Furtheron we analyze the tax evasion dynamics for different agent compositions and under the feedback of public goods provision. We conclude that policymakers may enhance tax compliance behavior via the threshold of perception by means of targeted public relations. Y1 - 2014 UR - http://cejeme.eu/publishedarticles/2014-35-24-635550501521093750-4578.pdf SN - 2080-0886 VL - 6 IS - 4 SP - 217 EP - 236 ER - TY - GEN A1 - Seibold, Götz A1 - Pickhardt, Michael T1 - Lapse of time effects on tax evasion in an agent-based econophysics model T2 - Physica A: Statistical Mechanics and its Applications N2 - We investigate an inhomogeneous Ising model in the context of tax evasion dynamics where different types of agents are parameterized via local temperatures and magnetic fields. In particular, we analyze the impact of lapse of time effects (i.e. backauditing) and endogenously determined penalty rates on tax compliance. Both features contribute to a microfoundation of agent-based econophysics models of tax evasion. Y1 - 2013 UR - http://www.sciencedirect.com/science/article/pii/S0378437113000307 U6 - https://doi.org/10.1016/j.physa.2013.01.016 SN - 0378-4371 VL - 392 IS - 9 SP - 2079 EP - 2087 ER - TY - CHAP A1 - Bill, Andreas A1 - Hizhnyakov, Vladimir A1 - Seibold, Götz A1 - Sigmund, Ernst ED - Bussmann-Holder, Annette T1 - Electronic Inhomogeneities and Pairing from Unscreened Interactions in High-Tc Superconductors T2 - High-Tc Superconductors and Related Transition Metal Oxides Y1 - 2007 SN - 978-3-540-71022-6 SP - 143 EP - 156 PB - Springer CY - Berlin [u.a.] ER - TY - GEN A1 - Günther, Falk A1 - Seibold, Götz T1 - Elektronische Inhomogenitäten in Hochtemperatursupraleitern T2 - Forum der Forschung Y1 - 2005 SN - 0947-6989 VL - 9 IS - 18 SP - 41 EP - 48 ER - TY - GEN A1 - Seibold, Götz A1 - Varlamov, Sergej T1 - Effect of incommensurate charge-density wave scattering on theelectronic structure of high-Tc cuprates (II) T2 - Journal of Superconductivity Y1 - 2002 SN - 0896-1107 VL - 15 IS - 6 SP - 505 EP - 506 ER - TY - JOUR A1 - Bill, Andreas A1 - Hizhnyakov, Vladimir A1 - Nevedrov, D. A1 - Seibold, Götz A1 - Sigmund, Ernst T1 - Electronic inhomogeneities, electron-lattice and pairinginteractions in high-Tc superconductors Y1 - 1997 ER - TY - JOUR A1 - Sigmund, Ernst A1 - Seibold, Götz A1 - Bill, Andreas A1 - Wulf, Ulrich A1 - Isenmann, G. A1 - Essl, W. T1 - Dynamische Eigenschaften von Festkörpern und Molekularen Strukturen Y1 - 1995 ER - TY - JOUR A1 - Seibold, Götz A1 - Sigmund, Ernst T1 - Gutzwiller and Slave-Boson Methods for Intersite Coulomb Interactions Y1 - 1996 ER - TY - THES A1 - Seibold, Götz T1 - Spin-polarisierte Quasiteilchen in der Hochtemperatursupraleitung Y1 - 1995 PB - Aachen : Shaker ER - TY - JOUR A1 - Sigmund, Ernst A1 - Hizhnyakov, Vladimir A1 - Seibold, Götz T1 - Electronic Phase Separation in High-Tc Superconductors Y1 - 1994 ER - TY - JOUR A1 - Ruckh, R. A1 - Seibold, Götz A1 - Sigmund, Ernst T1 - Influence of quantum fluctuations on solitary-wave acoustic polaron motion Y1 - 1993 ER - TY - JOUR A1 - Seibold, Götz A1 - Sigmund, Ernst T1 - Metal-insulator transition in doped bismuthate superconductors Y1 - 1993 ER - TY - JOUR A1 - Seibold, Götz A1 - Sigmund, Ernst A1 - Hizhnyakov, Vladimir T1 - Spin-cluster states in CuO2 planes JF - Physical review B Y1 - 1993 SN - 0556-2805 VL - 48 IS - 10 SP - 7537 EP - 7544 ER - TY - JOUR A1 - Seibold, Götz A1 - Varlamov, Sergej T1 - Effective particle-particle interaction in incommensurable CDW systems Y1 - 2001 ER - TY - GEN A1 - Seibold, Götz A1 - Caprara, Sergio A1 - Grilli, Marco A1 - Raimondi, Roberto T1 - Theory of the Spin Galvanic Effect at Oxide Interfaces T2 - Physical Review Letters N2 - The spin galvanic effect (SGE) describes the conversion of a nonequilibrium spin polarization into a transverse charge current. Recent experiments have demonstrated a large conversion efficiency for the two-dimensional electron gas formed at the interface between two insulating oxides, LaAlO3 and SrTiO3. Here, we analyze the SGE for oxide interfaces within a three-band model for the Ti t2g orbitals which displays an interesting variety of effective spin-orbit couplings in the individual bands that contribute differently to the spin-charge conversion. Our analytical approach is supplemented by a numerical treatment where we also investigate the influence of disorder and temperature, which turns out to be crucial to providing an appropriate description of the experimental data. KW - Spin polarization KW - Spin-orbit coupling KW - Spintronics KW - Two-dimensional electron gas Y1 - 2017 UR - https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.256801 U6 - https://doi.org/10.1103/PhysRevLett.119.256801 SN - 1092-0145 VL - 119 IS - 25 ER - TY - GEN A1 - Seibold, Götz A1 - Grilli, Marco T1 - Influence of incommensurate dynamic charge-density wave scattering on the line shape of supersonducting high-Tc cuprates T2 - Physical review : B Y1 - 2001 SN - 1098-0121 IS - 22 SP - S. 224505 ER - TY - GEN A1 - Seibold, Götz A1 - Caprara, Sergio A1 - Grilli, Marco A1 - Raimondi, Roberto T1 - Intrinsic spin Hall effect in systems with striped spin-orbit coupling T2 - epl : a letters journal exploring the frontiers of physics KW - Condensed Matter Y1 - 2015 UR - http://epljournal.edpsciences.org/articles/epl/abs/2015/19/epl17411/epl17411.html U6 - https://doi.org/http://dx.doi.org/10.1209/0295-5075/112/17004 SN - 1286-4854 VL - 112 IS - 1 SP - 17004-p1 EP - 17004-p6 ER - TY - GEN A1 - Seibold, Götz A1 - Udina, Mattia A1 - Castellani, Claudio A1 - Benfatto, Lara T1 - Third harmonic generation from collective modes in disordered superconductors T2 - Physical Review B N2 - Recent experiments with strong THz fields in both conventional and unconventional superconductors have clearly evidenced a marked third-harmonic generation below the superconducting temperature Tc. Its interpretation challenged substantial theoretical work aimed at establishing the relative efficiency of quasiparticle excitations and collective modes in triggering such a resonant response. Here we compute the nonlinear current by implementing a time-dependent Bogoljubov–de Gennes approach, with the twofold aim to account nonperturbatively for the effect of local disorder, and to include the contribution of all collective modes, i.e., superconducting amplitude (Higgs) and phase fluctuations, and charge fluctuations. We show that, in agreement with previous work, already at small disorder the quasiparticle response is dominated by paramagnetic effects. We further demonstrate that paramagnetic processes mediate also the response of all collective modes, with a substantial contribution of charge/phase fluctuations. These processes, which have been overlooked so far, turn out to dominate the third-order current at strong disorder. In addition, we show that disorder strongly influences the polarization dependence of the nonlinear response, with a marked difference between the clean and the disordered case. Our results are particularly relevant for recent experiments in cuprates, whose band structure is in a first approximation reproduced by our lattice model. KW - High-order harmonic generation KW - Impurities in superconductors KW - Optical & microwave phenomena KW - Quasiparticles & collective excitations KW - Superconductivity KW - Disordered systems KW - Higgs bosons KW - Bogoliubov-de Gennes equations Y1 - 2021 UR - https://journals.aps.org/prb/abstract/10.1103/PhysRevB.103.014512 U6 - https://doi.org/10.1103/PhysRevB.103.014512 VL - 103 IS - 1 ER - TY - GEN A1 - Seibold, Götz A1 - Castellani, Claudio A1 - Lorenzana, José T1 - Adiabatic transition from a BCS superconductor to a Fermi liquid and phase dynamics T2 - Physical Review B N2 - We investigate the physics of an adiabatic transition from a BCS superconductor to a Fermi liquid for an exponentially slow decreasing pairing interaction. We show that, depending on the order of the thermodynamic limit and large times, a situation can arise in which the Fermi liquid keeps a memory of the parent BCS state. Furthermore, a time inversion of the interaction, supplemented by a manipulation analogous to a spin-/photon-echo experiment, allows us to recover the parent BCS state. Moreover, we study the evolution of the order parameter phase ϕ in transforming the BCS superconductor to a conventional metal. Since the global phase is the conjugate variable of the density, we explicitly show how to use the dynamics of ϕ together with gauge invariance to build up the noninteracting chemical potential away from particle-hole symmetry. We further analyze the role of ϕ in restoring the gauge-invariant current response when the noninteracting Fermi liquid is approached starting from a BCS superconductor in the presence of an external vector field. KW - Superconductivity KW - Nonequilibrium systems KW - Adiabatic approximation KW - BCS theory KW - Gauge symmetries KW - Variational approach Y1 - 2022 UR - https://journals.aps.org/prb/abstract/10.1103/PhysRevB.105.184513 U6 - https://doi.org/10.1103/PhysRevB.105.184513 SN - 2469-9969 VL - 105 IS - 18 SP - 184513-1 EP - 184513-14 ER - TY - GEN A1 - Caprara, Sergio A1 - Di Castro, Carlo A1 - Mirarchi, Giovanni A1 - Seibold, Götz A1 - Grilli, Marco T1 - Dissipation-driven strange metal behavior T2 - Communications Physics N2 - Anomalous metallic properties are often observed in the proximity of quantum critical points, with violation of the Fermi Liquid paradigm. We propose a scenario where, near the quantum critical point, dynamical fluctuations of the order parameter with finite correlation length mediate a nearly isotropic scattering among the quasiparticles over the entire Fermi surface. This scattering produces a strange metallic behavior, which is extended to the lowest temperatures by an increase of the damping of the fluctuations. We phenomenologically identify one single parameter ruling this increasing damping when the temperature decreases, accounting for both the linear-in-temperature resistivity and the seemingly divergent specific heat observed, e.g., in high-temperature superconducting cuprates and some heavy-fermion metals. KW - Electronic properties and materials KW - Superconducting properties and materials Y1 - 2022 UR - https://www.nature.com/articles/s42005-021-00786-y U6 - https://doi.org/10.1038/s42005-021-00786-y SN - 2399-3650 IS - 5 SP - 1 EP - 7 ER - TY - GEN A1 - Seibold, Götz A1 - Arpaia, Riccardo A1 - Ying Ying, Peng A1 - Fumagalli, Roberto A1 - Braicovich, Lucio A1 - Di Castro, Carlo A1 - Grilli, Marco A1 - Ghiringhelli, Giacomo Claudio A1 - Caprara, Sergio T1 - Strange metal behaviour from charge density fluctuations in cuprates T2 - Communications Physics N2 - Besides the mechanism responsible for high critical temperature superconductivity, the grand unresolved issue of the cuprates is the occurrence of a strange metallic state above the so-called pseudogap temperature T*. Even though such state has been successfully described within a phenomenological scheme, the so-called Marginal Fermi-Liquid theory, a microscopic explanation is still missing. However, recent resonant X-ray scattering experiments identified a new class of charge density fluctuations characterized by low characteristic energies and short correlation lengths, which are related to the well-known charge density waves. These fluctuations are present over a wide region of the temperature-vs-doping phase diagram and extend well above T*. Here we investigate the consequences of charge density fluctuations on the electron and transport properties and find that they can explain the strange metal phenomenology. Therefore, charge density fluctuations are likely the long-sought microscopic mechanism underlying the peculiarities of the metallic state of cuprates. KW - Electronic properties and materials KW - Superconducting properties and materials Y1 - 2021 UR - https://www.nature.com/articles/s42005-020-00505-z U6 - https://doi.org/10.1038/s42005-020-00505-z SN - 2399-3650 VL - 4 SP - 1 EP - 6 ER - TY - GEN A1 - Seibold, Götz A1 - Benfatto, Lara A1 - Castellani, Claudio T1 - Application of the Mattis-Bardeen theory in strongly disordered superconductors T2 - Physical Review B N2 - The low-energy optical conductivity of conventional superconductors is usually well described by Mattis-Bardeen (MB) theory, which predicts the onset of absorption above an energy corresponding to twice the superconducing (SC) gap parameter Δ. Recent experiments on strongly disordered superconductors have challenged the application of the MB formulas due to the occurrence of additional spectral weight at low energies below 2Δ. Here we identify three crucial items that have to be included in the analysis of optical-conductivity data for these systems: (a) the correct identification of the optical threshold in the Mattis-Bardeen theory and its relation with the gap value extracted from the measured density of states, (b) the gauge-invariant evaluation of the current-current response function needed to account for the optical absorption by SC collective modes, and (c) the inclusion into the MB formula of the energy dependence of the density of states present already above Tc. By computing the optical conductivity in the disordered attractive Hubbard model, we analyze the relevance of all these items, and we provide a compelling scheme for the analysis and interpretation of the optical data in real materials. KW - Superconductivity KW - Superconductivity fluctuations KW - Impurities in superconductors Y1 - 2017 UR - https://journals.aps.org/prb/abstract/10.1103/PhysRevB.96.144507 U6 - https://doi.org/10.1103/PhysRevB.96.144507 VL - 96 IS - 14 SP - 144507 ER - TY - GEN A1 - Noatschk, Katharina A1 - Hofmann, E. V. S. A1 - Dabrowski, J. A1 - Curson, N. J. A1 - Schröder, Thomas A1 - Klesse, Wolfgang Matthias A1 - Seibold, Götz T1 - Ge(001) surface reconstruction with Sn impurities T2 - Surface Science N2 - Defects play an important role for surface reconstructions and therefore also influence the substrate growth. In this work we present a first principle calculation for the Ge(001) surface without and with tin impurities incorporated into the top surface layer. By mapping the system onto an Ising-type model, with interaction constants taken from density functional theory, the stability of the surface reconstructions under the influence of different concentrations of tin impurities is explored. This approach allows us to simulate the possible phase transitions for the different surface reconstructions including the local structure around the tin impurity atoms. In addition, we compare our theoretical results with experimental STM images on clean and Sn-doped Ge(100) surfaces. KW - Gesn KW - DFT KW - Monte carlo simulations KW - Surface reconstruction KW - Impurities Y1 - 2021 UR - https://www.sciencedirect.com/science/article/pii/S0039602821001163?dgcid=author U6 - https://doi.org/10.1016/j.susc.2021.121912 VL - 713 SP - 1 EP - 8 ER - TY - GEN A1 - Oelsen, E. von A1 - Di Ciolo, A. A1 - Lorenzana, José A1 - Seibold, Götz A1 - Grilli, Marco T1 - Phonon renormalization from local and transitive electron-latticecouplings in strongly correlated systems Y1 - 2010 ER - TY - JOUR A1 - Lorenzana, José A1 - Seibold, Götz A1 - Ortix, C. A1 - Grilli, Marco T1 - Competing orders in FeAs layers Y1 - 2008 ER - TY - GEN A1 - Tea, C. A1 - Castellani, Claudio A1 - Seibold, Götz A1 - Benfatto, Lara T1 - Nonrelativistic Dynamics of the Amplitude (Higgs) Mode in Superconductors T2 - Physical Review Letters Y1 - 2015 UR - https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.115.157002 U6 - https://doi.org/http://dx.doi.org/10.1103/PhysRevLett.115.157002 SN - 1079-7114 VL - 115 SP - 157002 ER - TY - GEN A1 - Di Ciolo, A. A1 - Lorenzana, José A1 - Grilli, Marco A1 - Seibold, Götz T1 - Charge instabilities and electron-phonon interaction in the Hubbard-Holstein model T2 - Physical Review B KW - strongly correlated systems Y1 - 2009 SN - 1550-235X VL - 79 SP - 085101 ER - TY - GEN A1 - Mirarchi, Giovanni A1 - Seibold, Götz A1 - Di Castro, Carlo A1 - Grilli, Marco A1 - Caprara, Sergio T1 - The Strange-Metal Behavior of Cuprates T2 - Condensed Matter N2 - Recent resonant X-ray scattering experiments on cuprates allowed to identify a new kind of collective excitations, known as charge density fluctuations, which have finite characteristic wave vector, short correlation length and small characteristic energy. It was then shown that these fluctuations provide a microscopic scattering mechanism that accounts for the anomalous transport properties of cuprates in the so-called strange-metal phase and are a source of anomalies in the specific heat. In this work, we retrace the main steps that led us to attributing a central role to charge density fluctuations in the strange-metal phase of cuprates, discuss the state of the art on the issue and provide an in-depth analysis of the contribution of charge density fluctuations to the specific heat. KW - high-temperature superconductors KW - cuprates KW - charge density fluctuations KW - strange metal KW - dynamical quantum criticality Y1 - 2022 UR - https://www.mdpi.com/2410-3896/7/1/29/htm U6 - https://doi.org/10.3390/condmat7010029 SN - 2410-3896 VL - 7 IS - 1 SP - 1 EP - 17 ER - TY - GEN A1 - Lemarié, Gabriel A1 - Kamlapure, Anand A1 - Benfatto, Lara A1 - Lorenzana, José A1 - Seibold, Götz A1 - Ganguli, S. C. A1 - Raychaudhuri, Pratap A1 - Castellani, Claudio T1 - Universal scaling of the order-parameter distribution in strongly disordered superconductors T2 - Physical Review B N2 - We investigate theoretically and experimentally the statistical properties of the inhomogeneous order-parameter distribution (OPD) at the verge of the superconductor-insulator transition (SIT). We find within two prototype fermionic and bosonic models for disordered superconductors that one can identify a universal rescaling of the OPD. By performing scanning-tunneling microscopy experiments in three samples of NbN with increasing disorder we show that such a rescaling also describes the experimental data with excellent accuracy. These results can provide a breakthrough in our understanding of the SIT. Y1 - 2013 UR - http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.184509 U6 - https://doi.org/10.1103/PhysRevB.87.184509 SN - 2469-9977 VL - 87 IS - 18 SP - 184509 ER - TY - GEN A1 - Mondal, Mintu A1 - Kumar, Sanjeev A1 - Chand, Madhavi A1 - Kamlapure, Anand A1 - Saraswat, Garima A1 - Seibold, Götz A1 - Benfatto, Lara A1 - Raychaudhuri, Pratap T1 - Role of the Vortex-Core Energy on the Berezinskii-Kosterlitz-Thouless Transition in Thin Films of NbN Y1 - 2011 U6 - https://doi.org/10.1103/PhysRevLett.107.217003 ER - TY - GEN A1 - Seibold, Götz A1 - Becca, Federico A1 - Bucci, F. A1 - Castellani, Claudio A1 - Di Castro, Carlo A1 - Grilli, Marco T1 - Spectral properties of incommensurate charge-density wave systems Y1 - 2000 ER - TY - JOUR A1 - Seibold, Götz A1 - Becca, Federico A1 - Lorenzana, José T1 - Time dependent Gutzwiller theory of pairing fluctuations in the Hubbard model JF - Physical Review B KW - Correlated electrons KW - Hubbard mode KW - Pairing correlations Y1 - 2008 SN - 0556-2805 VL - 78 SP - 045114 ER - TY - JOUR A1 - Lorenzana, José A1 - Seibold, Götz T1 - Unified description of charge and spin excitations of stripes in cuprates Y1 - 2007 ER - TY - JOUR A1 - Di Ciolo, A. A1 - Lorenzana, José A1 - Seibold, Götz A1 - Grilli, Marco T1 - Paramagnetic stripes in cuprates: charge inhomogeneity coexisting with large Fermi surfaces Y1 - 2007 ER - TY - GEN A1 - Seibold, Götz A1 - Castellani, Claudio A1 - Di Castro, Carlo T1 - Fermi surface and electronic structure of incommensurate charge-density-wave systems Y1 - 2000 ER - TY - JOUR A1 - Seibold, Götz A1 - Becca, Federico A1 - Lorenzana, José T1 - Inhomogeneous Gutzwiller approximation with random phase fluctuationsfor the Hubbard model Y1 - 2003 ER - TY - JOUR A1 - Guenther, Falk A1 - Seibold, Götz A1 - Lorenzana, José T1 - Quantum Lifshitz point in the infinite dimensional Hubbard model Y1 - 2007 ER - TY - GEN A1 - Bill, Andreas A1 - Hizhnyakov, Vladimir A1 - Kremer, Reinhard K. A1 - Seibold, Götz A1 - Shelkan, Aleksander A1 - Sherman, Aleksei T1 - Phase Separation and Pairing Fluctuations in Oxide Materials T2 - Condensed Matter N2 - The microscopic mechanism of charge instabilities and the formation of inhomogeneous states in systems with strong electron correlations is investigated. We demonstrate that within a strong coupling expansion the single-band Hubbard model shows an instability towards phase separation and extend the approach also for an analysis of phase separation in the Hubbard-Kanamori hamiltonian as a prototypical multiband model. We study the pairing fluctuations on top of an inhomogeneous stripe state where superconducting correlations in the extended s-wave and d-wave channels correspond to (anti)bound states in the two-particle spectra. Whereas extended s-wave fluctuations are relevant on the scale of the local interaction parameter U, we find that d-wave fluctuations are pronounced in the energy range of the active subband which crosses the Fermi level. As a result, low energy spin and charge fluctuations can transfer the d-wave correlations from the bound states to the low energy quasiparticle bands. Our investigations therefore help to understand the coexistence of stripe correlations and d-wave superconductivity in cuprates. KW - phase separation KW - cuprate superconductors KW - electronic correlations Y1 - 2020 UR - https://www.mdpi.com/2410-3896/5/4/65/htm U6 - https://doi.org/10.3390/condmat5040065 SN - 2410-3896 VL - 5 IS - 4 ER - TY - GEN A1 - Seibold, Götz A1 - Capati, Matteo A1 - Grilli, Marco A1 - Di Castro, Carlo A1 - Grilli, Marco A1 - Lorenzana, José T1 - Hidden ferronematic order in underdoped cuprates T2 - Physical Review B N2 - We study a model for low-doped cuprates where holes aggregate into oriented stripe segments which have a magnetic vortex and antivortex at the extremes. We argue that due to the interaction between segments a ferronematic state with macroscopic polarization is stabilized. This state can be characterized as a charge nematic which, due to the net polarization, breaks inversion symmetry and also exhibits an incommensurate spin modulation. Our calculation can reproduce the doping-dependent spin structure factor of lanthanum cuprates in excellent agreement with experiment and allows to rationalize experiments in which the incommensurability has an order-parameter-like temperature dependence. Y1 - 2013 UR - http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.035138 U6 - https://doi.org/10.1103/PhysRevB.87.035138 SN - 2469-9969 VL - 87 IS - 3 SP - 035138 ER - TY - GEN A1 - Noatschk, Katharina A1 - Martens, Christian A1 - Seibold, Götz T1 - Time-Dependent Gutzwiller Approximation: Theory and Applications T2 - Journal of Superconductivity and Novel Magnetism N2 - The time-dependent Gutzwiller approximation is rederived on the basis of a variational wave function which is a direct product of a Slater determinant and a coherent state. The latter can be related to the slave-boson formulation by Kotliar and Ruckenstein, and our approach offers a convenient way to generalize the theory towards the implementation of symmetry-broken states and the study of non-equilibrium phenomena. We discuss the concept with regard to applications in the linear response limit and for quenched antiferromagnetic order for which we evaluate the optical conductivity in non-equilibrium situations. KW - Hubbard model KW - Gutzwiller approximation KW - Non-equilibrium Y1 - 2020 UR - https://link.springer.com/article/10.1007/s10948-019-05406-z#Sec1 U6 - https://doi.org/10.1007/s10948-019-05406-z VL - 33 IS - 8 SP - 2389 EP - 2393 ER - TY - JOUR A1 - Müller, Sebastian A1 - Seibold, Götz A1 - Schmeißer, Dieter ED - Vierhaus, Heinrich Theodor T1 - Preparation and Characterization of TiO2 Thin Films and Cr and Co Doped TiO2 Thin Films Y1 - 2007 ER - TY - JOUR A1 - Seibold, Götz A1 - Lorenzana, José T1 - Doping dependence of spin excitations in the stripe phase of high-Tc superconductors Y1 - 2006 ER - TY - GEN A1 - Seibold, Götz A1 - Di Castro, Carlo A1 - Grilli, Marco A1 - Lorenzana, José T1 - Spin excitations of ferronematic order in underdoped cuprate superconductors T2 - Scientific reports N2 - High-temperature superconductors exhibit a characteristic hourglass-shaped spectrum of magnetic fluctuations which most likely contribute to the pairing glue in the cuprates. Recent neutron scattering experiments in strongly underdoped compounds have revealed a significant low energy anisotropy of these fluctuations which we explain by a model in which topological defects of the antiferromagnet clump to producing domain wall segments with ferronematic order. This state does not invoke global charge order but breaks C4 rotational and inversion symmetry. The incommensurability of the low doping charge-disordered state is in good agreement with experiment and interpolates smoothly with the incommensurability of the stripe phase at higher doping. Within linear spin-wave theory the dynamic structure factor is in very good agreement with inelastic neutron scattering data and can account for the observed energy dependent anisotropy. Y1 - 2014 UR - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4060504/ U6 - https://doi.org/10.1038/srep05319 SN - 2045-2322 IS - 4 SP - 5319 ER - TY - GEN A1 - Markiewicz, Richard S. A1 - Lorenzana, José A1 - Seibold, Götz T1 - Gutzwiller magnetic phase diagram of the undoped $ t- t' -U $ Hubbard model Y1 - 2010 ER - TY - GEN A1 - Bünemann, Jörg A1 - Capone, Michael A1 - Lorenzana, José A1 - Seibold, Götz T1 - Linear-response dynamics from the time-dependent Gutzwiller approximation T2 - New Journal of Physics N2 - Within a Lagrangian formalism, we derive the time-dependent Gutzwiller approximation for general multi-band Hubbard models. Our approach explicitly incorporates the coupling between time-dependent variational parameters and a time-dependent density matrix from which we obtain dynamical correlation functions in the linear-response regime. Our results are illustrated for the one-band model where we show that the interacting system can be mapped to an effective problem of fermionic quasiparticles coupled to 'doublon' (double occupancy) bosonic fluctuations. The latter have an energy on the scale of the on-site Hubbard repulsion U in the dilute limit but become soft at the Brinkman–Rice transition, which is shown to be related to an emerging conservation law of doublon charge and the associated gauge invariance. Coupling with the boson mode produces a structure in the charge response and we find that a similar structure appears in dynamical mean-field theory. Y1 - 2013 UR - http://iopscience.iop.org/article/10.1088/1367-2630/15/5/053050 SN - 1367-2630 VL - 15 ER - TY - GEN A1 - Seibold, Götz A1 - Grilli, Marco A1 - Lorenzana, José T1 - Stripes in cuprate superconductors: Excitations and dynamic dichotomy T2 - Physica C: Superconductivity N2 - We present a short account of the present experimental situation of stripes in cuprates followed by a review of our present understanding of their ground state and excited state properties. Collective modes, the dynamical structure factor, and the optical conductivity of stripes are computed using the time-dependent Gutzwiller approximation applied to realistic one band and three band Hubbard models, and are found to be in excellent agreement with experiment. On the other hand, experiments like angle-resolved photoemission and scanning tunneling microscopy show the coexistence of stripes at high energies with Fermi liquid quasiparticles at low energies. We show that a phenomenological model going beyond mean-field can reconcile this dynamic dichotomy. Y1 - 2012 UR - http://www.sciencedirect.com/science/article/pii/S0921453412001864 U6 - https://doi.org/10.1016/j.physc.2012.03.072 SN - 0921-4534 VL - 481 SP - 132 EP - 145 ER - TY - GEN A1 - Hizhnyakov, Vladimir A1 - Seibold, Götz T1 - Nanoscale phase separation in cuprate superconductors T2 - Physica C: Superconductivity and its Applications N2 - Electronic inhomogeneities are nowadays a well established feature of high-temperature superconductors, most prominently exemplified by the observation of charge-ordered states in a large number of cuprate materials. In this contribution we review the particular contribution of the Stuttgart-Tartu-Cottbus group to this field, which has been largely stimulated by intense discussion with K. Alex Müller. The original scenario, which was based on the formation of a percolative electronic network, is substantiated by a microscopic analysis of the clustering of magnetic polarons within the one-band Hubbard model. KW - Cuprates KW - Superconductors KW - Phase separation KW - Electronic inhomogeneities Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S0921453423001004 U6 - https://doi.org/10.1016/j.physc.2023.1354309 SN - 1873-2143 VL - 612 SP - 1 EP - 7 ER - TY - GEN A1 - Seibold, Götz A1 - Benfatto, Lara A1 - Castellani, Claudio A1 - Lorenzana, José T1 - Current Correlations in Strongly Disordered Superconductors T2 - Journal of Superconductivity and Novel Magnetism Y1 - 2016 UR - http://link.springer.com/article/10.1007%2Fs10948-015-3300-6 U6 - https://doi.org/10.1007/s10948-015-3300-6 VL - 29 IS - 3 SP - 577 EP - 580 ER - TY - JOUR A1 - Seibold, Götz A1 - Lorenzana, José T1 - Stability of metallic stripes in the extended one-band Hubbard model Y1 - 2004 ER - TY - GEN A1 - Markiewicz, Richard S. A1 - Lorenzana, José A1 - Seibold, Götz A1 - Bansil, Arun T1 - Short range smectic order driving long range nematic order: example of cuprates T2 - Scientific reports Y1 - 2016 UR - http://www.nature.com/articles/srep19678 U6 - https://doi.org/10.1038/srep19678 SN - 2045-2322 VL - 6 SP - 19678 ER - TY - JOUR A1 - Günther, Falk A1 - Seibold, Götz T1 - Time-dependent Gutzwiller theory of pair fluctuations in the Hubbard model Y1 - 2007 ER - TY - GEN A1 - Benfatto, Lara A1 - Castellani, Claudio A1 - Seibold, Götz T1 - Linear and nonlinear current response in disordered d-wave superconductors T2 - Physical Review B N2 - We present a detailed theoretical investigation of the linear and nonlinear optical response in a model system for a disordered d-wave superconductor. By evaluating the quasiparticle contribution (BCS response) we show that for both quantities the gap symmetry considerably changes the paradigm of the optical response as compared to the conventional s-wave case. For what concerns the linear response our findings agree with previous work showing that in strongly disordered d-wave superconductors a large fraction of uncondensed spectral weight survives below Tc, making the optical absorption around the gap-frequency scale almost unchanged with respect to the normal state. Our numerical results are in excellent quantitative agreement with experiments in overdoped cuprates. In the nonlinear regime we focus on the third-harmonic generation (THG), finding that, as already established for the s-wave case, in general a large THG is triggered by disorder-activated paramagnetic processes. However, in the d-wave case the BCS response is monotonously increasing in frequency, losing any signature of THG enhancement when the THz pump frequency ω matches the gap maximum Δ, a hallmark of previous experiments in conventional s-wave superconductors. Our findings, along with the mild polarization dependence of the response, provide an explanation for recent THG measurements in cuprates, setting the framework for the theoretical understanding of nonlinear effects in unconventional cuprates. KW - Superconducting order parameter KW - Superfluid density KW - High-temperature superconductors KW - Superconductivity KW - Drude model KW - Numerical techniques KW - Reflectivity KW - Terahertz spectroscopy Y1 - 2023 UR - https://journals.aps.org/prb/abstract/10.1103/PhysRevB.108.134508 U6 - https://doi.org/10.1103/PhysRevB.108.134508 SN - 2469-9969 SN - 2469-9950 VL - 108 SP - 134508-1 EP - 134508-15 ER - TY - GEN A1 - Seibold, Götz A1 - Castellani, Claudio A1 - Di Castro, Carlo A1 - Grilli, Marco T1 - Fermi surface and photoemission lineshape of incommensurate CDW systems Y1 - 2000 ER - TY - JOUR A1 - Sigmund, Ernst A1 - Hizhnyakov, Vladimir A1 - Seibold, Götz T1 - Phase-Separation in High-Tc Superconductors JF - Physica C : Superconductivity Y1 - 1994 SN - 0921-4534 VL - Vol. 235–240 IS - 1 SP - 253 EP - 256 ER - TY - JOUR A1 - Seibold, Götz A1 - Grilli, Marco A1 - Lorenzana, José T1 - Checkerboard and stripe inhomogeneities in cuprates JF - Physical review B Y1 - 2007 SN - 1550-235X VL - 75 IS - 10 SP - 10050(R) ER - TY - GEN A1 - Ugenti, S. A1 - Cini, M. A1 - Seibold, Götz A1 - Lorenzana, José A1 - Perfetto, E. A1 - Stefanucci, G. T1 - Particle-particle response function as a probe for electronic correlations in the p-d Hubbard model Y1 - 2010 ER - TY - GEN A1 - Seibold, Götz A1 - Varlamov, Sergej T1 - Effect of incommensurate charge-density wave scattering on theelectronic structure of high-Tc cuprates (I) T2 - Journal of Superconductivity Y1 - 2002 SN - 0896-1107 VL - 15 IS - 5 SP - 387 EP - 388 ER - TY - CHAP A1 - Seibold, Götz A1 - Castellani, Claudio A1 - Di Castro, Carlo A1 - Grilli, Marco ED - Bianconi, Antonio ED - Saini, Naurang L. T1 - Domain wall structures in the two-dimensional Hubbard modelwith long-range Coulomb interaction T2 - Stripes and Related Phenomena Y1 - 2000 SN - 0-306-46419-5 U6 - https://doi.org/10.1007/0-306-47100-0_18 SP - 151 EP - 157 PB - Kluwer Academic Plenum CY - New York ER - TY - GEN A1 - Seibold, Götz A1 - Grilli, Marco A1 - Lorenzana, José T1 - Model of Quasiparticles Coupled to a Frequency-Dependent Charge-DensityWave Order Parameter in Cuprate Superconductors Y1 - 2009 ER - TY - GEN A1 - Seibold, Götz A1 - Markiewicz, Richard S. A1 - Lorenzana, José T1 - Stripes with Spin Canting in the Three-Band Hubbard Model T2 - Journal of Superconductivity and Novel Magnetism N2 - In underdoped cuprates, both stripes and spiral states may account for the incommensurate spin response observed by elastic neutron scattering experiments. Here, we investigate the respective stability of both textures within the framework of the three-band Hubbard model which we treat within the unrestricted Gutzwiller approximation. Our calculations indicate that for parameter sets appropriate for lanthanum cuprates and small doping nor purely longitudinal stripes nor uniform spirals are stable but stripes with significant spin canting. Indeed at small doping uniform spirals are unstable toward nanoscale phase separation. KW - Stripes KW - Spirals KW - High-temperature superconductors Y1 - 2013 UR - http://link.springer.com/article/10.1007/s10948-012-1701-3 U6 - https://doi.org/10.1007/s10948-012-1701-3 SN - 1557-1939 SN - 1557-1947 VL - 26 IS - 1 SP - 49 EP - 52 ER - TY - GEN A1 - Seibold, Götz A1 - Castellani, Claudio A1 - Di Castro, Carlo A1 - Grilli, Marco T1 - Striped phases in the two-dimensional Hubbard model with long-rangeCoulomb interaction Y1 - 1998 ER - TY - GEN A1 - Seibold, Götz A1 - Lorenzana, José T1 - Diagonal stripes in the spin glass phase of cuprates T2 - Physica : C Y1 - 2009 N1 - Proceedings of the 9th International Conference on Materials andMechanisms of Superconductivity VL - 470 IS - Suppl. 1 SP - 245 EP - 246 ER - TY - GEN A1 - Seibold, Götz A1 - Markiewicz, Richard S. A1 - Lorenzana, José T1 - Magnetic Structure of Electronic Inhomogeneities in Cuprates: Competition between Stripes and Spirals T2 - Acta Physica Polonica A N2 - It is shown that the magnetic structure of high-T c superconductors is strongly influenced by the next-nearest neighbor hopping parameter t' which distinguishes different families of cuprates. Our investigations indicate that uniform spirals get favored by a large t'=t ratio but are unstable at small doping towards stripes with spin canting. For large /t'/t/ spirals can be stabilized under certain conditions in the overdoped regime which may explain the elastic incommensurate magnetic response recently observed in iron-co-doped Bi2201 materials. Y1 - 2012 UR - https://www.researchgate.net/publication/230739012_Magnetic_Structure_of_Electron ic_Inhomogeneities_in_Cuprates_Competition_between_Stripes_and_Spirals SN - 1898-794X VL - 121 IS - 5-6 SP - 1019 EP - 1021 ER - TY - GEN A1 - Seibold, Götz A1 - Castellani, Claudio A1 - Di Castro, Carlo A1 - Grilli, Marco ED - Barnes, Stewart E. T1 - Role of the long-range Coulomb interaction on the formation of striped phases in the two-dimensional Hubbard model T2 - High temperature superconductivity, Coral Gables, Florida, January 1999 Y1 - 1999 SN - 1-56396-880-0 U6 - https://doi.org/10.1063/1.59651 PB - AIP Publishing CY - Melville, New York ER - TY - GEN A1 - Seibold, Götz A1 - Grilli, Marco A1 - Lorenzana, José T1 - Dynamical charge and spin density wave scattering in cuprate superconductors Y1 - 2010 ER - TY - GEN A1 - Capati, Matteo A1 - Caprara, Sergio A1 - Di Castro, Carlo A1 - Grilli, Marco A1 - Seibold, Götz A1 - Lorenzana, José T1 - Electronic polymers and soft-matter-like broken symmetries in underdoped cuprates T2 - Nature Communications N2 - Empirical evidence in heavy fermion, pnictide and other systems suggests that unconventional superconductivity appears associated to some form of real-space electronic order. For the cuprates, despite several proposals, the emergence of order in the phase diagram between the commensurate antiferromagnetic state and the superconducting state is not well understood. Here we show that in this regime doped holes assemble in ‘electronic polymers’. Within a Monte Carlo study, we find that in clean systems by lowering the temperature the polymer melt condenses first in a smectic state and then in a Wigner crystal both with the addition of inversion symmetry breaking. Disorder blurs the positional order leaving a robust inversion symmetry breaking and a nematic order, accompanied by vector chiral spin order and with the persistence of a thermodynamic transition. Such electronic phases, whose properties are reminiscent of soft-matter physics, produce charge and spin responses in good accord with experiments. KW - Molecular electronics KW - Polymers KW - Superconducting properties and materials Y1 - 2015 UR - http://www.nature.com/articles/ncomms8691 U6 - https://doi.org/doi:10.1038/ncomms8691 SN - 2041-1723 VL - 6 SP - 7691 ER - TY - GEN A1 - Cea, Tommaso A1 - Bucheli, Daniel A1 - Seibold, Götz A1 - Benfatto, Lara A1 - Lorenzana, José A1 - Castellani, Claudio T1 - Optical excitation of phase modes in strongly disordered superconductors T2 - Physical Review B N2 - According to the Goldstone theorem the breaking of a continuous U(1) symmetry comes along with the existence of low-energy collective modes. In the context of superconductivity these excitations are related to the phase of the superconducting (SC) order parameter and for clean systems are optically inactive; that is, single-mode excitations do not directly couple to light. Here we show that for strongly disordered superconductors phase modes acquire a dipole moment and appear as a subgap spectral feature in the optical conductivity. This finding is obtained with both a gauge-invariant random-phase approximation scheme based on a fermionic Bogoliubov–de Gennes state and a prototypical bosonic model for disordered superconductors. In the strongly disordered regime, where the system displays an effective granularity of the SC properties, the optically active dipoles are linked to the isolated SC islands, offering a new perspective for realizing microwave optical devices. Y1 - 2014 UR - http://journals.aps.org/prb/abstract/10.1103/PhysRevB.89.174506 U6 - https://doi.org/10.1103/PhysRevB.89.174506 SN - 2469-9969 VL - 89 SP - 174506 ER - TY - GEN A1 - Seibold, Götz A1 - Benfatto, Lara A1 - Castellani, Claudio A1 - Lorenzana, José T1 - Amplitude, density, and current correlations of strongly disordered superconductors T2 - Physical Review B N2 - We investigate the disorder dependence of the static density, amplitude, and current correlations within the attractive Hubbard model supplemented with onsite disorder. It is found that strong disorder favors a decoupling of density and amplitude correlations due to the formation of superconducting (SC) islands. This emergent granularity also induces an enhancement of the density correlations on the SC islands whereas amplitude fluctuations are most pronounced in the “insulating” regions. While density and amplitude correlations are short ranged at strong disorder, we show that current correlations have a long-range tail due to the formation of percolative current paths in agreement with the constant behavior expected from the analysis of one-dimensional models. Y1 - 2015 UR - http://journals.aps.org/prb/abstract/10.1103/PhysRevB.92.064512 U6 - https://doi.org/10.1103/PhysRevB.92.064512 SN - 2469-9969 VL - 92 IS - 6 SP - 064512 ER - TY - GEN A1 - Markiewicz, Richard S. A1 - Lorenzana, José A1 - Seibold, Götz A1 - Bansil, Arun T1 - Competing phases on the cuprates: Charge vs spin order Y1 - 2011 ER - TY - GEN A1 - Grilli, Marco A1 - Seibold, Götz A1 - Di Ciolo, A. A1 - Lorenzana, José T1 - Fermi surface dichotomy in systems with fluctuating order T2 - Physical Review B Y1 - 2009 SN - 1550-235X VL - 79 SP - 125111 ER - TY - JOUR A1 - Seibold, Götz A1 - Becca, Federico A1 - Rubin, P. A1 - Lorenzana, José T1 - Time-dependent Gutzwiller theory of magnetic excitations in the Hubbard model Y1 - 2004 ER - TY - GEN A1 - Seibold, Götz A1 - Grilli, Marco A1 - Lorenzana, José T1 - Influence of correlations on transitive electron-phonon couplings in cuprate superconductors Y1 - 2011 ER - TY - JOUR A1 - Seibold, Götz A1 - Sigmund, Ernst T1 - Differences between one and multiband Hubbard models Y1 - 1995 ER - TY - GEN A1 - Caprara, Sergio A1 - Grilli, Marco A1 - Di Castro, Carlo A1 - Seibold, Götz T1 - Pseudogap and (An)isotropic Scattering in the Fluctuating Charge-Density Wave Phase of Cuprates T2 - Journal of Superconductivity and Novel Magnetism N2 - We present a general scenario for high-temperature superconducting cuprates, based on the presence of dynamical charge density waves (CDWs) and to the occurrence of a CDW quantum critical point, which occurs, e.g., at doping p ≈ 0.16 in YBa2Cu3O6 + δ (YBCO). In this framework, the pseudogap temperature T∗ is interpreted in terms of a reduction of the density of states due to incipient CDW and, at lower temperature to the possible formation of incoherent superconducting pairs. The dynamically fluctuating character of CDW accounts for the different temperatures at which the CDW onset revealed by X-ray scattering (Tons(p)), and the static three-dimensional CDW ordering appear. We also investigate the anisotropic character of the CDW-mediated scattering. We find that this is strongly anisotropic only close to the CDW quantum critical point (QCP) at low temperature and very low energy. It rapidly becomes nearly isotropic and marginal-Fermi-liquid-like away from the CDW QCP and at finite (even rather small) energies. This may reconcile the interpretation of Hall measurements in terms of anisotropic CDW scattering with recent photoemission experiments Bok, J.M., et al. Sci. Adv. 2, e1501329 (2016). KW - Charge-density waves KW - High-Tc superconducting cuprates KW - Anisotropic scattering Y1 - 2017 UR - http://link.springer.com/article/10.1007/s10948-016-3775-9 U6 - https://doi.org/10.1007/s10948-016-3775-9 SN - 1557-1939 SN - 1557-1947 VL - 30 IS - 1 SP - 25 EP - 30 ER - TY - GEN A1 - Martens, Christian A1 - Bill, Andreas A1 - Seibold, Götz T1 - Phase separation and proximity effects in itinerant ferromagnet/superconductor heterostructures T2 - Physical Review B N2 - Heterostructures made of itinerant ferromagnets and superconductors are studied. In contrast to most previous models, ferromagnetism is not enforced by an effective Zeeman field but induced in a correlated single-band model (CSBM) that displays itinerant ferromagnetism as a mean-field ground state. In this model superconductivity and magnetism are both calculated self-consistently. We calculate the magnitude of the magnetization, the superconducting correlations, and variations of the charge density self-consistently for a superconducting-magnetic bilayer by solving the Bogoliubov–de Gennes equations on a two-dimensional lattice. We determine all three quantities as a function of the Coulomb repulsion U and the ferromagnetic exchange interaction J. The CSBM displays a variety of features not present in the Zeeman exchange model—for example, the occurrence of electronic phase separation and the competition of magnetic and superconducting orders far away from the interface. KW - charge order KW - Exchange interaction KW - Ferromagnetism KW - Local density of states KW - Microphase separation KW - Proximity effect KW - Superconducting order parameter Y1 - 2018 U6 - https://doi.org/10.1103/PhysRevB.98.174513 SN - 2469-9969 SN - 1095-3795 VL - 98 IS - 17 ER - TY - CHAP A1 - Bill, Andreas A1 - Hizhnyakov, Vladimir A1 - Seibold, Götz ED - Bussmann-Holder, Annette ED - Keller, Hugo ED - Bianconi, Antonio T1 - Electronic Phase Separation and Electron–Phonon Coupling in Cuprate Superconductors T2 - High-Tc Copper Oxide Superconductors and Related Novel Materials N2 - Nanoscale electronic inhomogeneities are nowadays a well established feature of high-temperature superconductors, most prominently exemplified by the observation of charge-ordered states in a large number of cuprate materials. These inhomogeneities have profound consequences for the electron–phonon coupling since they allow for long-range pairing interactions due to the reduced screening supplemented by the enhancement of the electron–phonon vertex due to strong correlations. In this chapter we review the particular contribution of the Stuttgart-Tartu-Cottbus group to this field and discuss how the current status of experimental results provides affirmation to their ideas. KW - Strongly Correlated Systems KW - Optical and Electronic Materials KW - Nanochemistry KW - Ceramics KW - Spectroscopy and Microscopy KW - Superconductivity KW - Glass KW - Composites KW - Natural Materials Y1 - 2017 UR - http://link.springer.com/chapter/10.1007/978-3-319-52675-1_1 SN - 978-3-319-52674-4 SN - 978-3-319-52675-1 U6 - https://doi.org/10.1007/978-3-319-52675-1_1 SP - 1 EP - 14 PB - Springer International Publishing CY - Cham ER - TY - GEN A1 - Seibold, Götz A1 - Lorenzana, José T1 - Calculation of incommensurability and spin excitations of diagonal stripes in underdoped lanthanum cuprates T2 - Physical Review B Y1 - 2009 SN - 1550-235X VL - 80 IS - 1 SP - 012509 ER - TY - JOUR A1 - Seibold, Götz A1 - Varlamov, Sergej T1 - Spectral properties of incommensurate CDW scattering in cuprates Y1 - 2003 ER - TY - GEN A1 - Markiewicz, Richard S. A1 - Seibold, Götz A1 - Lorenzana, José A1 - Bansil, Arun T1 - Gutzwiller charge phase diagram of cuprates, including electron–phonon coupling effects T2 - New Journal of Physics N2 - Besides significant electronic correlations, high-temperature superconductors also show a strong coupling of electrons to a number of lattice modes. Combined with the experimental detection of electronic inhomogeneities and ordering phenomena in many high-Tc compounds, these features raise the question as to what extent phonons are involved in the associated instabilities. Here we address this problem based on the Hubbard model including a coupling to phonons in order to capture several salient features of the phase diagram of hole-doped cuprates. Charge degrees of freedom, which are suppressed by the large Hubbard U near half-filling, are found to become active at a fairly low doping level. We find that possible charge order is mainly driven by Fermi surface nesting, with competition between a near-$(\pi ,\pi )$ order at low doping and antinodal nesting at higher doping, very similar to the momentum structure of magnetic fluctuations. The resulting nesting vectors are generally consistent with photoemission and tunneling observations, evidence for charge density wave order in YBa2Cu3O$_{7-\delta }$ including Kohn anomalies, and suggestions of competition between one- and two-q-vector nesting. Y1 - 2015 UR - http://iopscience.iop.org/article/10.1088/1367-2630/17/2/023074/meta U6 - https://doi.org/10.1088/1367-2630/17/2/023074 SN - 1367-2630 VL - 17 IS - 2 SP - 023074 ER - TY - GEN A1 - Seibold, Götz A1 - Benfatto, Lara A1 - Castellani, Claudio A1 - Lorenzana, José T1 - Superfluid Density and Phase Relaxation in Superconductors with Strong Disorder T2 - Physical Review Letters N2 - We consider the attractive Hubbard model with on-site disorder as a prototype of a disordered superconductor. We solve the Bogoliubov–de Gennes equations on two-dimensional finite clusters at zero temperature and evaluate the electromagnetic response to a vector potential. We find that the standard decoupling between transverse and longitudinal response does not apply in the presence of disorder. Moreover, the superfluid density is strongly reduced by the relaxation of the phase of the order parameter already at mean-field level when disorder is large. We also find that the anharmonicity of the phase fluctuations is strongly enhanced by disorder. Beyond mean field, this provides an enhancement of quantum fluctuations inducing a zero-temperature transition to a nonsuperconducting phase of disordered preformed pairs. Finally, the connection of our findings with the glassy physics for extreme dirty superconductors is discussed. Y1 - 2012 UR - http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.108.207004 U6 - https://doi.org/10.1103/PhysRevLett.108.207004 SN - 1092-0145 VL - 108 IS - 20 SP - 207004 ER - TY - JOUR A1 - Seibold, Götz A1 - Varlamov, Sergej T1 - Relationship between incommensurability and superconductivity in Peierls distorted charge-density-wave systems JF - Physical review : B Y1 - 1999 SN - 0556-2805 VL - 60 SP - 13056 ER - TY - JOUR A1 - Varlamov, Sergej A1 - Seibold, Götz T1 - Effective interactions in the stripe state of the two-dimensional Hubbard model Y1 - 2002 ER - TY - CHAP A1 - Seibold, Götz ED - Hokamp, Sascha ED - Gulyas, Lazlo ED - Koehler, Matthew ED - Wijesinghe, Sanith T1 - From Spins to Agents: An Econophysics Approach to Tax Evasion T2 - Agent-based Modeling of Tax Evasion: Theoretical Aspects and Computational Simulations N2 - The only single-source guide to understanding, using, adapting, and designing state-of-the-art agent-based modeling of tax evasion A computational method for simulating the behaviour of individuals or groups and their effects on an entire system, agent-based modeling has proven itself to be a powerful new tool for detecting tax fraud. While interdisciplinary groups and individuals working in the tax domain have published numerous articles in diverse peer-reviewed journals and presented their findings at international conferences, until Agent-based Modeling of Tax Evasion there has been no authoritative, single-source guide to state-of-the-art agent-based tax evasion modeling techniques and technologies. Featuring contributions from distinguished experts in the field from around the globe, Agent-Based Modeling of Tax Evasion provides in-depth coverage of an array of field tested agent-based tax evasion models. Models are presented in a unified format so as to enable readers to systematically work their way through the various modeling alternatives available to them. Three main components of each agent-based model are explored in accordance with the Overview, Design Concepts, and Details (ODD) protocol, each section of which contains several sub elements that help to illustrate the model clearly and that assist readers in replicating the modeling results described. Presents models in a unified and structured manner to provide a point of reference for readers interested in agent-based modeling of tax evasion Explores the theoretical aspects and diversity of agent-based modeling through the example of tax evasion Provides an overview of the characteristics of more than thirty agent-based tax evasion frameworks Functions as a solid foundation for lectures and seminars on agent-based modeling of tax evasion The only comprehensive treatment of agent-based tax evasion models and their applications, this book is an indispensable working resource for practitioners and tax evasion modelers both in the agent-based computational domain and using other methodologies. It is also an excellent pedagogical resource for teaching tax evasion modeling and/or agent-based modeling generally. KW - General & Introductory Statistics KW - Applied Probability & Statistics Statistics for Finance" Business & Economics KW - Statistics for Finance" Business & Economics Y1 - 2018 SN - 978-1-119-15570-6 SP - 315 EP - 336 PB - Wiley CY - Weinheim ER - TY - GEN A1 - Bazart, Cécile A1 - Bonein, Aurélie A1 - Hokamp, Sascha A1 - Seibold, Götz T1 - Bahavioural Economics and Tax Evasion: Calibrating an Agent-based Econophysics Model with Experimental Tax Compliance Data T2 - Journal of Tax Administration Y1 - 2016 UR - http://jota.website/article/view/74 VL - 2 IS - 1 SP - 126 EP - 144 ER - TY - GEN A1 - Günther, Falk A1 - Seibold, Götz A1 - Lorenzana, José T1 - Stability of ferromagnetism within the time-dependent Gutzwiller approximation for the Hubbard model Y1 - 2011 ER - TY - JOUR A1 - Varlamov, Sergej A1 - Seibold, Götz T1 - Influence of the pseudogap on the superconductivity-inducedphonon renormalization in high-Tc superconductors Y1 - 2002 ER - TY - JOUR A1 - Seibold, Götz A1 - Lorenzana, José A1 - Coldea, Radu T1 - Sum rules and missing spectral weight in magnetic neutron scattering in the cuprates Y1 - 2005 ER - TY - JOUR A1 - Seibold, Götz A1 - Becca, Federico A1 - Lorenzana, José T1 - Theory of antibound states in partially filled narrow band systems Y1 - 2008 ER - TY - GEN A1 - Miao, Hu A1 - Lorenzana, José A1 - Seibold, Götz A1 - Peng, Yingying A1 - Amorese, Andrea A1 - Yakhou-Harris, Flora A1 - Kummer, Kurt A1 - Brookes, Nicholas B. A1 - Konik, R. M. A1 - Thampy, Vivek A1 - Gu, G. D. A1 - Ghiringhelli, Giacomo Claudio A1 - Braicovich, Lucio A1 - Dean, M. P. M. T1 - High-temperature charge density wave correlations in La1.875Ba0.125CuO4 without spin–charge locking T2 - Proceedings of the National Academy of Sciences of the United States of America PNAS N2 - Although all superconducting cuprates display charge-ordering tendencies, their low-temperature properties are distinct, impeding efforts to understand the phenomena within a single conceptual framework. While some systems exhibit stripes of charge and spin, with a locked periodicity, others host charge density waves (CDWs) without any obviously related spin order. Here we use resonant inelastic X-ray scattering to follow the evolution of charge correlations in the canonical stripe-ordered cuprate La1.875Ba0.125CuO4 across its ordering transition. We find that high-temperature charge correlations are unlocked from the wavevector of the spin correlations, signaling analogies to CDW phases in various other cuprates. This indicates that stripe order at low temperatures is stabilized by the coupling of otherwise independent charge and spin density waves, with important implications for the relation between charge and spin correlations in the cuprates. KW - charge density waves KW - stripes KW - high-temperature superconductivity KW - cuprates KW - X-rays Y1 - 2017 UR - http://www.pnas.org/content/early/2017/10/31/1708549114.abstract U6 - https://doi.org/10.1073/pnas.1708549114 SN - 1091-6490 SN - 0027-8424 VL - 114 IS - 47 SP - 12430 EP - 12435 ER - TY - GEN A1 - Schmeißer, Dieter A1 - Schmidt, Stephan A1 - Seibold, Götz A1 - Cherkashinin, Gennady A1 - Jaegermann, Wolfram T1 - Localized Gap States in LiCoO2 and their Influence on the Transport Properties in Li-Ion Batteries T2 - ECS Transactions Y1 - 2010 SN - 1938-5862 VL - 25 IS - 35 SP - 37 EP - 45 ER - TY - JOUR A1 - Seibold, Götz A1 - Lorenzana, José T1 - Magnetic excitations in the stripe phase of the Hubbard model Y1 - 2007 ER - TY - JOUR A1 - Lorenzana, José A1 - Seibold, Götz T1 - Metallic mean-field stripes, incommensurability and chemicalpotential in cuprates Y1 - 2002 ER - TY - GEN A1 - Wahlberg, Eric A1 - Arpaia, Riccardo A1 - Seibold, Götz A1 - Rossi, Matteo A1 - Fumagalli, Roberto A1 - Trabaldo, Edoardo A1 - Brookes, Nicholas B. A1 - Braicovich, Lucio A1 - Caprara, Sergio A1 - Lombardi, Floriana A1 - Gran, Ulf A1 - Ghiringhelli, Giacomo Claudio A1 - Bauch, Thilo T1 - Restored strange metal phase through suppression of charge density waves in underdoped YBa2Cu3O7–δ T2 - Science N2 - The normal state of optimally doped cuprates is dominated by the “strange metal” phase that shows a linear temperature (T) dependence of the resistivity persisting down to the lowest T. For underdoped cuprates, this behavior is lost below the pseudogap temperature T*, where charge density waves (CDWs), together with other intertwined local orders, characterize the ground state. We found that the T-linear resistivity of highly strained, ultrathin, underdoped YBa2Cu3O7–δ films is restored when the CDW amplitude, detected by resonant inelastic x-ray scattering, is suppressed. This observation suggests an intimate connection between the onset of CDWs and the departure from T-linear resistivity in underdoped cuprates. Our results illustrate the potential of using strain control to manipulate the ground state of quantum materials. KW - Cuprate superconductors KW - Charge-Density Wave Y1 - 2021 UR - https://www.science.org/doi/10.1126/science.abc8372 U6 - https://doi.org/10.1126/science.abc8372 VL - 373 IS - 6562 SP - 1506 EP - 1510 ER - TY - GEN A1 - Grilli, Marco A1 - Di Castro, Carlo A1 - Mirarchi, Giovanni A1 - Seibold, Götz A1 - Caprara, Sergio T1 - Dissipative Quantum Criticality as a Source of Strange Metal Behavior T2 - Symmetry N2 - The strange metal behavior, usually characterized by a linear-in-temperature (T) resistivity, is a still unsolved mystery in solid-state physics. It is often associated with the proximity to a quantum critical point (a second order transition at temperature T=0, leading to a broken symmetry phase) focusing on the related divergent order parameter correlation length. Here, we propose a paradigmatic shift, focusing on a divergent characteristic time scale due to a divergent dissipation acting on the fluctuating critical modes while their correlation length stays finite. To achieve a divergent dissipation, we propose a mechanism based on the coupling between a local order parameter fluctuation and electron density diffusive modes that accounts both for the linear-in-T resistivity and for the logarithmic specific heat versus temperature ratio CV/T∼log(1/T), down to low temperatures. KW - strange metal behavior KW - cuprates KW - charge density fluctuations KW - diffusive modes Y1 - 2023 U6 - https://doi.org/10.3390/sym15030569 SN - 2073-8994 VL - 15 IS - 3 ER -