@misc{SeiboldCastellaniLorenzana, author = {Seibold, G{\"o}tz and Castellani, Claudio and Lorenzana, Jos{\´e}}, title = {Adiabatic transition from a BCS superconductor to a Fermi liquid and phase dynamics}, series = {Physical Review B}, volume = {105}, journal = {Physical Review B}, number = {18}, issn = {2469-9969}, doi = {10.1103/PhysRevB.105.184513}, pages = {184513-1 -- 184513-14}, abstract = {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.}, language = {en} } @misc{CapraraDiCastroMirarchietal., author = {Caprara, Sergio and Di Castro, Carlo and Mirarchi, Giovanni and Seibold, G{\"o}tz and Grilli, Marco}, title = {Dissipation-driven strange metal behavior}, series = {Communications Physics}, journal = {Communications Physics}, number = {5}, issn = {2399-3650}, doi = {10.1038/s42005-021-00786-y}, pages = {1 -- 7}, abstract = {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.}, language = {en} } @misc{SeiboldArpaiaYingYingetal., author = {Seibold, G{\"o}tz and Arpaia, Riccardo and Ying Ying, Peng and Fumagalli, Roberto and Braicovich, Lucio and Di Castro, Carlo and Grilli, Marco and Ghiringhelli, Giacomo Claudio and Caprara, Sergio}, title = {Strange metal behaviour from charge density fluctuations in cuprates}, series = {Communications Physics}, volume = {4}, journal = {Communications Physics}, issn = {2399-3650}, doi = {10.1038/s42005-020-00505-z}, pages = {1 -- 6}, abstract = {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.}, language = {en} } @misc{SeiboldBenfattoCastellani, author = {Seibold, G{\"o}tz and Benfatto, Lara and Castellani, Claudio}, title = {Application of the Mattis-Bardeen theory in strongly disordered superconductors}, series = {Physical Review B}, volume = {96}, journal = {Physical Review B}, number = {14}, doi = {10.1103/PhysRevB.96.144507}, pages = {144507}, abstract = {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.}, language = {en} } @misc{NoatschkHofmannDabrowskietal., author = {Noatschk, Katharina and Hofmann, E. V. S. and Dabrowski, J. and Curson, N. J. and Schr{\"o}der, Thomas and Klesse, Wolfgang Matthias and Seibold, G{\"o}tz}, title = {Ge(001) surface reconstruction with Sn impurities}, series = {Surface Science}, volume = {713}, journal = {Surface Science}, doi = {10.1016/j.susc.2021.121912}, pages = {1 -- 8}, abstract = {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.}, language = {en} } @misc{OelsenDiCioloLorenzanaetal., author = {Oelsen, E. von and Di Ciolo, A. and Lorenzana, Jos{\´e} and Seibold, G{\"o}tz and Grilli, Marco}, title = {Phonon renormalization from local and transitive electron-latticecouplings in strongly correlated systems}, language = {en} } @article{LorenzanaSeiboldOrtixetal., author = {Lorenzana, Jos{\´e} and Seibold, G{\"o}tz and Ortix, C. and Grilli, Marco}, title = {Competing orders in FeAs layers}, language = {en} } @misc{TeaCastellaniSeiboldetal., author = {Tea, C. and Castellani, Claudio and Seibold, G{\"o}tz and Benfatto, Lara}, title = {Nonrelativistic Dynamics of the Amplitude (Higgs) Mode in Superconductors}, series = {Physical Review Letters}, volume = {115}, journal = {Physical Review Letters}, issn = {1079-7114}, doi = {http://dx.doi.org/10.1103/PhysRevLett.115.157002}, pages = {157002}, language = {en} } @misc{DiCioloLorenzanaGrillietal., author = {Di Ciolo, A. and Lorenzana, Jos{\´e} and Grilli, Marco and Seibold, G{\"o}tz}, title = {Charge instabilities and electron-phonon interaction in the Hubbard-Holstein model}, series = {Physical Review B}, volume = {79}, journal = {Physical Review B}, issn = {1550-235X}, pages = {085101}, language = {en} } @misc{MirarchiSeiboldDiCastroetal., author = {Mirarchi, Giovanni and Seibold, G{\"o}tz and Di Castro, Carlo and Grilli, Marco and Caprara, Sergio}, title = {The Strange-Metal Behavior of Cuprates}, series = {Condensed Matter}, volume = {7}, journal = {Condensed Matter}, number = {1}, issn = {2410-3896}, doi = {10.3390/condmat7010029}, pages = {1 -- 17}, abstract = {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.}, language = {en} } @misc{LemarieKamlapureBenfattoetal., author = {Lemari{\´e}, Gabriel and Kamlapure, Anand and Benfatto, Lara and Lorenzana, Jos{\´e} and Seibold, G{\"o}tz and Ganguli, S. C. and Raychaudhuri, Pratap and Castellani, Claudio}, title = {Universal scaling of the order-parameter distribution in strongly disordered superconductors}, series = {Physical Review B}, volume = {87}, journal = {Physical Review B}, number = {18}, issn = {2469-9977}, doi = {10.1103/PhysRevB.87.184509}, pages = {184509}, abstract = {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.}, language = {en} } @misc{MondalKumarChandetal., author = {Mondal, Mintu and Kumar, Sanjeev and Chand, Madhavi and Kamlapure, Anand and Saraswat, Garima and Seibold, G{\"o}tz and Benfatto, Lara and Raychaudhuri, Pratap}, title = {Role of the Vortex-Core Energy on the Berezinskii-Kosterlitz-Thouless Transition in Thin Films of NbN}, doi = {10.1103/PhysRevLett.107.217003}, language = {en} } @misc{SeiboldBeccaBuccietal., author = {Seibold, G{\"o}tz and Becca, Federico and Bucci, F. and Castellani, Claudio and Di Castro, Carlo and Grilli, Marco}, title = {Spectral properties of incommensurate charge-density wave systems}, language = {en} } @article{SeiboldBeccaLorenzana, author = {Seibold, G{\"o}tz and Becca, Federico and Lorenzana, Jos{\´e}}, title = {Time dependent Gutzwiller theory of pairing fluctuations in the Hubbard model}, series = {Physical Review B}, volume = {78}, journal = {Physical Review B}, issn = {0556-2805}, pages = {045114}, language = {en} } @article{LorenzanaSeibold, author = {Lorenzana, Jos{\´e} and Seibold, G{\"o}tz}, title = {Unified description of charge and spin excitations of stripes in cuprates}, language = {en} } @article{DiCioloLorenzanaSeiboldetal., author = {Di Ciolo, A. and Lorenzana, Jos{\´e} and Seibold, G{\"o}tz and Grilli, Marco}, title = {Paramagnetic stripes in cuprates: charge inhomogeneity coexisting with large Fermi surfaces}, language = {en} } @misc{SeiboldCastellaniDiCastro, author = {Seibold, G{\"o}tz and Castellani, Claudio and Di Castro, Carlo}, title = {Fermi surface and electronic structure of incommensurate charge-density-wave systems}, language = {en} } @article{SeiboldBeccaLorenzana, author = {Seibold, G{\"o}tz and Becca, Federico and Lorenzana, Jos{\´e}}, title = {Inhomogeneous Gutzwiller approximation with random phase fluctuationsfor the Hubbard model}, language = {en} } @article{GuentherSeiboldLorenzana, author = {Guenther, Falk and Seibold, G{\"o}tz and Lorenzana, Jos{\´e}}, title = {Quantum Lifshitz point in the infinite dimensional Hubbard model}, language = {en} } @misc{BillHizhnyakovKremeretal., author = {Bill, Andreas and Hizhnyakov, Vladimir and Kremer, Reinhard K. and Seibold, G{\"o}tz and Shelkan, Aleksander and Sherman, Aleksei}, title = {Phase Separation and Pairing Fluctuations in Oxide Materials}, series = {Condensed Matter}, volume = {5}, journal = {Condensed Matter}, number = {4}, issn = {2410-3896}, doi = {10.3390/condmat5040065}, pages = {23}, abstract = {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.}, language = {en} } @misc{SeiboldCapatiGrillietal., author = {Seibold, G{\"o}tz and Capati, Matteo and Grilli, Marco and Di Castro, Carlo and Grilli, Marco and Lorenzana, Jos{\´e}}, title = {Hidden ferronematic order in underdoped cuprates}, series = {Physical Review B}, volume = {87}, journal = {Physical Review B}, number = {3}, issn = {2469-9969}, doi = {10.1103/PhysRevB.87.035138}, pages = {035138}, abstract = {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.}, language = {en} } @misc{NoatschkMartensSeibold, author = {Noatschk, Katharina and Martens, Christian and Seibold, G{\"o}tz}, title = {Time-Dependent Gutzwiller Approximation: Theory and Applications}, series = {Journal of Superconductivity and Novel Magnetism}, volume = {33}, journal = {Journal of Superconductivity and Novel Magnetism}, number = {8}, doi = {10.1007/s10948-019-05406-z}, pages = {2389 -- 2393}, abstract = {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.}, language = {en} } @article{MuellerSeiboldSchmeisser, author = {M{\"u}ller, Sebastian and Seibold, G{\"o}tz and Schmeißer, Dieter}, title = {Preparation and Characterization of TiO2 Thin Films and Cr and Co Doped TiO2 Thin Films}, editor = {Vierhaus, Heinrich Theodor}, language = {en} } @article{SeiboldLorenzana, author = {Seibold, G{\"o}tz and Lorenzana, Jos{\´e}}, title = {Doping dependence of spin excitations in the stripe phase of high-Tc superconductors}, language = {en} } @misc{SeiboldDiCastroGrillietal., author = {Seibold, G{\"o}tz and Di Castro, Carlo and Grilli, Marco and Lorenzana, Jos{\´e}}, title = {Spin excitations of ferronematic order in underdoped cuprate superconductors}, series = {Scientific reports}, journal = {Scientific reports}, number = {4}, issn = {2045-2322}, doi = {10.1038/srep05319}, pages = {5319}, abstract = {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.}, language = {en} } @misc{MarkiewiczLorenzanaSeibold, author = {Markiewicz, Richard S. and Lorenzana, Jos{\´e} and Seibold, G{\"o}tz}, title = {Gutzwiller magnetic phase diagram of the undoped \$ t- t' -U \$ Hubbard model}, language = {en} } @misc{BuenemannCaponeLorenzanaetal., author = {B{\"u}nemann, J{\"o}rg and Capone, Michael and Lorenzana, Jos{\´e} and Seibold, G{\"o}tz}, title = {Linear-response dynamics from the time-dependent Gutzwiller approximation}, series = {New Journal of Physics}, volume = {15}, journal = {New Journal of Physics}, issn = {1367-2630}, abstract = {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.}, language = {en} } @misc{SeiboldGrilliLorenzana, author = {Seibold, G{\"o}tz and Grilli, Marco and Lorenzana, Jos{\´e}}, title = {Stripes in cuprate superconductors: Excitations and dynamic dichotomy}, series = {Physica C: Superconductivity}, volume = {481}, journal = {Physica C: Superconductivity}, issn = {0921-4534}, doi = {10.1016/j.physc.2012.03.072}, pages = {132 -- 145}, abstract = {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.}, language = {en} } @misc{HizhnyakovSeibold, author = {Hizhnyakov, Vladimir and Seibold, G{\"o}tz}, title = {Nanoscale phase separation in cuprate superconductors}, series = {Physica C: Superconductivity and its Applications}, volume = {612}, journal = {Physica C: Superconductivity and its Applications}, issn = {1873-2143}, doi = {10.1016/j.physc.2023.1354309}, pages = {1 -- 7}, abstract = {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 M{\"u}ller. 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.}, language = {en} } @misc{SeiboldBenfattoCastellanietal., author = {Seibold, G{\"o}tz and Benfatto, Lara and Castellani, Claudio and Lorenzana, Jos{\´e}}, title = {Current Correlations in Strongly Disordered Superconductors}, series = {Journal of Superconductivity and Novel Magnetism}, volume = {29}, journal = {Journal of Superconductivity and Novel Magnetism}, number = {3}, doi = {10.1007/s10948-015-3300-6}, pages = {577 -- 580}, language = {en} } @article{SeiboldLorenzana, author = {Seibold, G{\"o}tz and Lorenzana, Jos{\´e}}, title = {Stability of metallic stripes in the extended one-band Hubbard model}, language = {en} } @misc{MarkiewiczLorenzanaSeiboldetal., author = {Markiewicz, Richard S. and Lorenzana, Jos{\´e} and Seibold, G{\"o}tz and Bansil, Arun}, title = {Short range smectic order driving long range nematic order: example of cuprates}, series = {Scientific reports}, volume = {6}, journal = {Scientific reports}, issn = {2045-2322}, doi = {10.1038/srep19678}, pages = {19678}, language = {en} } @article{GuentherSeibold, author = {G{\"u}nther, Falk and Seibold, G{\"o}tz}, title = {Time-dependent Gutzwiller theory of pair fluctuations in the Hubbard model}, language = {en} } @misc{BenfattoCastellaniSeibold, author = {Benfatto, Lara and Castellani, Claudio and Seibold, G{\"o}tz}, title = {Linear and nonlinear current response in disordered d-wave superconductors}, series = {Physical Review B}, volume = {108}, journal = {Physical Review B}, issn = {2469-9969}, doi = {10.1103/PhysRevB.108.134508}, pages = {134508-1 -- 134508-15}, abstract = {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.}, language = {en} } @misc{SeiboldCastellaniDiCastroetal., author = {Seibold, G{\"o}tz and Castellani, Claudio and Di Castro, Carlo and Grilli, Marco}, title = {Fermi surface and photoemission lineshape of incommensurate CDW systems}, language = {en} } @article{SigmundHizhnyakovSeibold, author = {Sigmund, Ernst and Hizhnyakov, Vladimir and Seibold, G{\"o}tz}, title = {Phase-Separation in High-Tc Superconductors}, series = {Physica C : Superconductivity}, volume = {Vol. 235-240}, journal = {Physica C : Superconductivity}, number = {1}, issn = {0921-4534}, pages = {253 -- 256}, language = {en} } @article{SeiboldGrilliLorenzana, author = {Seibold, G{\"o}tz and Grilli, Marco and Lorenzana, Jos{\´e}}, title = {Checkerboard and stripe inhomogeneities in cuprates}, series = {Physical review B}, volume = {75}, journal = {Physical review B}, number = {10}, issn = {1550-235X}, pages = {10050(R)}, language = {en} } @misc{UgentiCiniSeiboldetal., author = {Ugenti, S. and Cini, M. and Seibold, G{\"o}tz and Lorenzana, Jos{\´e} and Perfetto, E. and Stefanucci, G.}, title = {Particle-particle response function as a probe for electronic correlations in the p-d Hubbard model}, language = {en} } @misc{SeiboldVarlamov, author = {Seibold, G{\"o}tz and Varlamov, Sergej}, title = {Effect of incommensurate charge-density wave scattering on theelectronic structure of high-Tc cuprates (I)}, series = {Journal of Superconductivity}, volume = {15}, journal = {Journal of Superconductivity}, number = {5}, issn = {0896-1107}, pages = {387 -- 388}, language = {en} } @incollection{SeiboldCastellaniDiCastroetal., author = {Seibold, G{\"o}tz and Castellani, Claudio and Di Castro, Carlo and Grilli, Marco}, title = {Domain wall structures in the two-dimensional Hubbard modelwith long-range Coulomb interaction}, series = {Stripes and Related Phenomena}, booktitle = {Stripes and Related Phenomena}, editor = {Bianconi, Antonio and Saini, Naurang L.}, publisher = {Kluwer Academic Plenum}, address = {New York}, isbn = {0-306-46419-5}, doi = {10.1007/0-306-47100-0_18}, pages = {151 -- 157}, language = {en} } @misc{SeiboldGrilliLorenzana, author = {Seibold, G{\"o}tz and Grilli, Marco and Lorenzana, Jos{\´e}}, title = {Model of Quasiparticles Coupled to a Frequency-Dependent Charge-DensityWave Order Parameter in Cuprate Superconductors}, language = {en} } @misc{SeiboldMarkiewiczLorenzana, author = {Seibold, G{\"o}tz and Markiewicz, Richard S. and Lorenzana, Jos{\´e}}, title = {Stripes with Spin Canting in the Three-Band Hubbard Model}, series = {Journal of Superconductivity and Novel Magnetism}, volume = {26}, journal = {Journal of Superconductivity and Novel Magnetism}, number = {1}, issn = {1557-1939}, doi = {10.1007/s10948-012-1701-3}, pages = {49 -- 52}, abstract = {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.}, language = {en} } @misc{SeiboldCastellaniDiCastroetal., author = {Seibold, G{\"o}tz and Castellani, Claudio and Di Castro, Carlo and Grilli, Marco}, title = {Striped phases in the two-dimensional Hubbard model with long-rangeCoulomb interaction}, language = {en} } @misc{SeiboldLorenzana, author = {Seibold, G{\"o}tz and Lorenzana, Jos{\´e}}, title = {Diagonal stripes in the spin glass phase of cuprates}, series = {Physica : C}, volume = {470}, journal = {Physica : C}, number = {Suppl. 1}, pages = {245 -- 246}, language = {en} } @misc{SeiboldMarkiewiczLorenzana, author = {Seibold, G{\"o}tz and Markiewicz, Richard S. and Lorenzana, Jos{\´e}}, title = {Magnetic Structure of Electronic Inhomogeneities in Cuprates: Competition between Stripes and Spirals}, series = {Acta Physica Polonica A}, volume = {121}, journal = {Acta Physica Polonica A}, number = {5-6}, issn = {1898-794X}, pages = {1019 -- 1021}, abstract = {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.}, language = {en} } @misc{SeiboldCastellaniDiCastroetal., author = {Seibold, G{\"o}tz and Castellani, Claudio and Di Castro, Carlo and Grilli, Marco}, title = {Role of the long-range Coulomb interaction on the formation of striped phases in the two-dimensional Hubbard model}, series = {High temperature superconductivity, Coral Gables, Florida, January 1999}, journal = {High temperature superconductivity, Coral Gables, Florida, January 1999}, editor = {Barnes, Stewart E.}, publisher = {AIP Publishing}, address = {Melville, New York}, isbn = {1-56396-880-0}, doi = {10.1063/1.59651}, language = {en} } @misc{SeiboldGrilliLorenzana, author = {Seibold, G{\"o}tz and Grilli, Marco and Lorenzana, Jos{\´e}}, title = {Dynamical charge and spin density wave scattering in cuprate superconductors}, language = {en} } @misc{CapatiCapraraDiCastroetal., author = {Capati, Matteo and Caprara, Sergio and Di Castro, Carlo and Grilli, Marco and Seibold, G{\"o}tz and Lorenzana, Jos{\´e}}, title = {Electronic polymers and soft-matter-like broken symmetries in underdoped cuprates}, series = {Nature Communications}, volume = {6}, journal = {Nature Communications}, issn = {2041-1723}, doi = {doi:10.1038/ncomms8691}, pages = {7691}, abstract = {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.}, language = {en} } @misc{CeaBucheliSeiboldetal., author = {Cea, Tommaso and Bucheli, Daniel and Seibold, G{\"o}tz and Benfatto, Lara and Lorenzana, Jos{\´e} and Castellani, Claudio}, title = {Optical excitation of phase modes in strongly disordered superconductors}, series = {Physical Review B}, volume = {89}, journal = {Physical Review B}, issn = {2469-9969}, doi = {10.1103/PhysRevB.89.174506}, pages = {174506}, abstract = {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.}, language = {en} } @misc{SeiboldBenfattoCastellanietal., author = {Seibold, G{\"o}tz and Benfatto, Lara and Castellani, Claudio and Lorenzana, Jos{\´e}}, title = {Amplitude, density, and current correlations of strongly disordered superconductors}, series = {Physical Review B}, volume = {92}, journal = {Physical Review B}, number = {6}, issn = {2469-9969}, doi = {10.1103/PhysRevB.92.064512}, pages = {064512}, abstract = {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.}, language = {en} }