@misc{BergerHokampSeibold, author = {Berger, Wolfram and Hokamp, Sascha and Seibold, G{\"o}tz}, title = {Dynamic behavioral changes in an agent-based econophysics tax compliance model. Bomb-crater versus target effects and efficient audit strategies}, series = {Journal of Public Finance and Public Choice}, volume = {36}, journal = {Journal of Public Finance and Public Choice}, number = {1}, issn = {2515-6926}, doi = {10.1332/251569120X15840237292628}, pages = {3 -- 24}, abstract = {We investigate an inhomogeneous Ising model in the context of tax evasion dynamics where different types of agents are parametrised via local temperatures and magnetic fields. Our work focuses on the dynamic behavioural change of agents after an audit which either corresponds to a temporal reduction or enhancement of compliance and is also known under the terms 'bomb crater' and 'target effect', respectively. We analyse this effect for different types of agents: endogenously non-compliant types, agents that have the tendency to copy (non-)compliant behaviour from their social environment, ethical agents with strong endogenous morale attitudes and random types that show large uctuations between compliant and non-compliant behaviour. Each type in uences the overall tax evasion differently, and interestingly, our model predicts that increasing the audit probability can have the counterintuitive effect of increasing tax evasion under certain circumstances. We analyse audit strategies that can suppress this effect and thus contribute to the burgeoning literature on the actual impact of tax audits.}, language = {en} } @article{SeiboldSigmundHizhnyakov, author = {Seibold, G{\"o}tz and Sigmund, Ernst and Hizhnyakov, Vladimir}, title = {Unrestricted slave-boson mean-field approximation for the two-dimensional Hubbard model}, series = {Physical review}, volume = {57}, journal = {Physical review}, number = {12}, issn = {0556-2805}, pages = {6937 -- 6942}, language = {en} } @misc{Seibold, author = {Seibold, G{\"o}tz}, title = {Vortex, skyrmion and elliptical domain wall textures in thetwo-dimensional Hubbard model}, series = {Physical review B}, volume = {58}, journal = {Physical review B}, number = {23}, issn = {1550-235X}, pages = {15520 -- 15527}, language = {en} } @article{LorenzanaSeibold, author = {Lorenzana, Jos{\´e} and Seibold, G{\"o}tz}, title = {Dynamics of metallic stripes in cuprates}, language = {en} } @misc{UdinaFioroCeaetal., author = {Udina, Mattia and Fioro, Jacopo and Cea, Tommaso and Castellani, Claudio and Seibold, G{\"o}tz and Benfatto, Lara}, title = {THz non-linear optical response in cuprates: predominance of the BCS response over the Higgs mode}, series = {Faraday Discussions}, volume = {237}, journal = {Faraday Discussions}, issn = {1364-5498}, doi = {10.1039/D2FD00016D}, pages = {168 -- 185}, abstract = {Recent experiments with strong THz fields in unconventional cuprate superconductors have clearly evidenced an increase of the non-linear optical response below the superconducting critical temperature Tc. As in the case of conventional superconductors, a theoretical estimate of the various effects contributing to the non-linear response is needed in order to interpret the experimental findings. Here, we report a detailed quantitative analysis of the non-linear THz optical kernel in cuprates within a realistic model, accounting for the band structure and disorder level appropriate for these systems. We show that the BCS quasiparticle response is the dominant contribution for cuprates, and its polarization dependence accounts very well for the third-harmonic generation measurements. On the other hand, the polarization dependence of the THz Kerr effect is only partly captured by our calculations, suggesting the presence of additional effects when the system is probed using light pulses with different central frequencies.}, language = {en} } @misc{MarkiewiczLorenzanaSeiboldetal., author = {Markiewicz, Richard S. and Lorenzana, Jos{\´e} and Seibold, G{\"o}tz and Bansil, Arun}, title = {Gutzwiller magnetic phase diagram of the cuprates}, language = {en} } @article{LorenzanaSeibold, author = {Lorenzana, Jos{\´e} and Seibold, G{\"o}tz}, title = {Dynamic properties of inhomogeneous states in cuprates}, language = {en} } @misc{BuenemannSeibold, author = {B{\"u}nemann, J{\"o}rg and Seibold, G{\"o}tz}, title = {Charge and pairing dynamics in the attractive Hubbard model: Mode coupling and the validity of linear-response theory}, series = {Physical Review B}, volume = {96}, journal = {Physical Review B}, number = {24}, issn = {2469-9977}, doi = {10.1103/PhysRevB.96.245139}, abstract = {Pump-probe experiments have turned out as a powerful tool in order to study the dynamics of competing orders in a large variety of materials. The corresponding analysis of the data often relies on standard linear-response theory generalized to nonequilibrium situations. Here we examine the validity of such an approach for the charge and pairing response of systems with charge-density wave and (or) superconducting (SC) order. Our investigations are based on the attractive Hubbard model which we study within the time-dependent Hartree-Fock approximation. In particular, we calculate the quench and pump-probe dynamics for SC and charge order parameters in order to analyze the frequency spectra and the coupling of the probe field to the specific excitations. Our calculations reveal that the "linear-response assumption" is justified for small to moderate nonequilibrium situations (i.e., pump pulses) in the case of a purely charge-ordered ground state. However, the pump-probe dynamics on top of a superconducting ground state is determined by phase and amplitude modes which get coupled far from the equilibrium state indicating the failure of the linear-response assumption.}, language = {en} } @misc{MiaoFumagalliRossietal., author = {Miao, Hu and Fumagalli, Roberto and Rossi, M. and Lorenzana, Jos{\´e} and Seibold, G{\"o}tz and Yakhou-Harris, Flora and Kummer, K. and Brookes, Nicholas B. and Gu, G. D. and Braicovich, Lucio and Ghiringhelli, Giacomo Claudio and Dean, M. P. M.}, title = {Formation of Incommensurate Charge Density Waves in Cuprates}, series = {Physical Review X}, volume = {9}, journal = {Physical Review X}, number = {3}, issn = {2160-3308}, doi = {10.1103/PhysRevX.9.031042}, pages = {031042-1 -- 031042-11}, abstract = {Although charge density waves (CDWs) are omnipresent in cuprate high-temperature superconductors, they occur at significantly different wave vectors, confounding efforts to understand their formation mechanism. Here, we use resonant inelastic x-ray scattering to investigate the doping- and temperature-dependent CDW evolution in La₂₋ₓBaₓCuO₄ (x=0.115-0.155). We discover that the CDW develops in two stages with decreasing temperature. A precursor CDW with a quasicommensurate wave vector emerges first at high temperature. This doping-independent precursor CDW correlation originates from the CDW phase mode coupled with a phonon and "seeds" the low-temperature CDW with a strongly doping-dependent wave vector. Our observation reveals the precursor CDW and its phase mode as the building blocks of the highly intertwined electronic ground state in the cuprates.}, language = {en} } @misc{MartensSeibold, author = {Martens, Christian and Seibold, G{\"o}tz}, title = {Non-equilibrium dynamics of stripes in cuprate superconductors}, series = {Journal of Magnetism and Magnetic Materials}, volume = {543}, journal = {Journal of Magnetism and Magnetic Materials}, issn = {1873-4766}, doi = {10.1016/j.jmmm.2021.168565}, pages = {1 -- 4}, abstract = {We use the time-dependent Gutzwiller approximation for the single-band Hubbard model to analyze the non-equilibrium dynamics for stripe ground states. In particular, we are interested in the interplay between spin and charge dynamics which is analyzed by quenching the system either in the charge or spin sector. This allows us to investigate the coupled relaxation dynamics as a function of the supplied energy. Further insight is provided by mapping the Gutzwiller dynamics onto a time-dependent Landau approach which lacks the double occupancy contribution to the time-evolution but allows to tune the coupling between spin- and charge degrees of freedom.}, language = {en} }