@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} } @misc{MarkiewiczLorenzanaSeiboldetal., author = {Markiewicz, Richard S. and Lorenzana, Jos{\´e} and Seibold, G{\"o}tz and Bansil, Arun}, title = {Competing phases on the cuprates: Charge vs spin order}, language = {en} } @misc{GrilliSeiboldDiCioloetal., author = {Grilli, Marco and Seibold, G{\"o}tz and Di Ciolo, A. and Lorenzana, Jos{\´e}}, title = {Fermi surface dichotomy in systems with fluctuating order}, series = {Physical Review B}, volume = {79}, journal = {Physical Review B}, issn = {1550-235X}, pages = {125111}, language = {en} } @article{SeiboldBeccaRubinetal., author = {Seibold, G{\"o}tz and Becca, Federico and Rubin, P. and Lorenzana, Jos{\´e}}, title = {Time-dependent Gutzwiller theory of magnetic excitations in the Hubbard model}, language = {en} } @misc{SeiboldGrilliLorenzana, author = {Seibold, G{\"o}tz and Grilli, Marco and Lorenzana, Jos{\´e}}, title = {Influence of correlations on transitive electron-phonon couplings in cuprate superconductors}, language = {en} } @article{SeiboldSigmund, author = {Seibold, G{\"o}tz and Sigmund, Ernst}, title = {Differences between one and multiband Hubbard models}, language = {en} } @misc{CapraraGrilliDiCastroetal., author = {Caprara, Sergio and Grilli, Marco and Di Castro, Carlo and Seibold, G{\"o}tz}, title = {Pseudogap and (An)isotropic Scattering in the Fluctuating Charge-Density Wave Phase of Cuprates}, series = {Journal of Superconductivity and Novel Magnetism}, volume = {30}, journal = {Journal of Superconductivity and Novel Magnetism}, number = {1}, issn = {1557-1939}, doi = {10.1007/s10948-016-3775-9}, pages = {25 -- 30}, abstract = {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).}, language = {en} } @misc{MartensBillSeibold, author = {Martens, Christian and Bill, Andreas and Seibold, G{\"o}tz}, title = {Phase separation and proximity effects in itinerant ferromagnet/superconductor heterostructures}, series = {Physical Review B}, volume = {98}, journal = {Physical Review B}, number = {17}, issn = {2469-9969}, doi = {10.1103/PhysRevB.98.174513}, pages = {10}, abstract = {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.}, language = {en} } @incollection{BillHizhnyakovSeibold, author = {Bill, Andreas and Hizhnyakov, Vladimir and Seibold, G{\"o}tz}, title = {Electronic Phase Separation and Electron-Phonon Coupling in Cuprate Superconductors}, series = {High-Tc Copper Oxide Superconductors and Related Novel Materials}, booktitle = {High-Tc Copper Oxide Superconductors and Related Novel Materials}, editor = {Bussmann-Holder, Annette and Keller, Hugo and Bianconi, Antonio}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-319-52674-4}, doi = {10.1007/978-3-319-52675-1_1}, pages = {1 -- 14}, abstract = {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.}, language = {en} } @misc{SeiboldLorenzana, author = {Seibold, G{\"o}tz and Lorenzana, Jos{\´e}}, title = {Calculation of incommensurability and spin excitations of diagonal stripes in underdoped lanthanum cuprates}, series = {Physical Review B}, volume = {80}, journal = {Physical Review B}, number = {1}, issn = {1550-235X}, pages = {012509}, language = {en} }