# High-temperature superconductivity in the two-dimensional t-J model: Gutzwiller wavefunction solution

 dc.identifier.uri http://dx.doi.org/10.15488/388 dc.identifier.uri http://www.repo.uni-hannover.de/handle/123456789/411 dc.contributor.author Kaczmarczyk, Jan dc.contributor.author Buenemann, Joerg dc.contributor.author Spalek, Jozef dc.date.accessioned 2016-08-12T08:08:31Z dc.date.available 2016-08-12T08:08:31Z dc.date.issued 2014-07-14 dc.identifier.citation Kaczmarczyk, Jan; Buenemann, Joerg; Spalek, Jozef: High-temperature superconductivity in the two-dimensional t-J model: Gutzwiller wavefunction solution. In: New Journal of Physics 16 (2014), 73018. DOI: http://dx.doi.org/10.1088/1367-2630/16/7/073018 dc.description.abstract A systematic diagrammatic expansion for Gutzwiller wavefunctions (DE-GWFs) proposed very recently is used for the description of the superconducting (SC) ground state in the two-dimensional square-lattice t–J model with the hopping electron amplitudes t (and $t^{\prime}$) between nearest (and next-nearest) neighbors. For the example of the SC state analysis we provide a detailed comparison of the methodʼs results with those of other approaches. Namely, (i) the truncated DE-GWF method reproduces the variational Monte Carlo (VMC) results and (ii) in the lowest (zeroth) order of the expansion the method can reproduce the analytical results of the standard Gutzwiller approximation (GA), as well as of the recently proposed 'grand-canonical Gutzwiller approximation' (called either GCGA or SGA). We obtain important features of the SC state. First, the SC gap at the Fermi surface resembles a ${{d}_{{{x}^{2}}-{{y}^{2}}}}$ wave only for optimally and overdoped systems, being diminished in the antinodal regions for the underdoped case in a qualitative agreement with experiment. Corrections to the gap structure are shown to arise from the longer range of the real-space pairing. Second, the nodal Fermi velocity is almost constant as a function of doping and agrees semi-quantitatively with experimental results. Third, we compare the doping dependence of the gap magnitude with experimental data. Fourth, we analyze the k-space properties of the model: Fermi surface topology and effective dispersion. The DE-GWF method opens up new perspectives for studying strongly correlated systems, as it (i) works in the thermodynamic limit, (ii) is comparable in accuracy to VMC, and (iii) has numerical complexity comparable to that of the GA (i.e., it provides the results much faster than the VMC approach). eng dc.description.sponsorship Foundation for Polish Science (FNP)/TEAM program dc.description.sponsorship National Science Centre (NCN)/MAESTRO dc.language.iso eng dc.publisher Bristol : IOP Publishing Ltd. dc.relation.ispartofseries New Journal of Physics 16 (2014) dc.rights CC BY 3.0 Unported dc.rights.uri https://creativecommons.org/licenses/by/3.0/de/ dc.subject t-J model eng dc.subject high-temperature superconductivity eng dc.subject Gutzwiller wave function eng dc.subject unconventional superconductivity eng dc.subject variational Monte-Carlo method eng dc.subject mean-field theory eng dc.subject dimensional fermi-surface eng dc.subject hubbard-model eng dc.subject state eng dc.subject transition eng dc.subject pseudogap eng dc.subject oxides eng dc.subject instability eng dc.subject competition eng dc.subject ansatz eng dc.subject.ddc 530 | Physik ger dc.title High-temperature superconductivity in the two-dimensional t-J model: Gutzwiller wavefunction solution eng dc.type article dc.type Text dc.relation.essn 1367-2630 dc.relation.doi http://dx.doi.org/10.1088/1367-2630/16/7/073018 dc.bibliographicCitation.volume 16 dc.bibliographicCitation.firstPage 73018 dc.description.version publishedVersion tib.accessRights frei zug�nglich
﻿