arXiv:0708.0788 · Physical Review B
Unidirectional d -wave superconducting domains in the two-dimensional t−J model
Marcin Raczkowski, Manuela Capello, Didier Poilblanc, Raymond Frésard, Andrzej M. Oleś
Abstract
Motivated by the recently observed pattern of unidirectional domains in high-${T}_{c}$ superconductors [Y. Kohsaka et al., Science 315, 1380 (2007)], we investigate the emergence of spontaneous modulations in the $d$-wave superconducting resonating valence bond phase using the $t$-$J$ model at $x=1∕8$ doping. Half-filled charge domains separated by four lattice spacings are found to form along one of the crystal axes, leading to modulated superconductivity with out-of-phase $d$-wave order parameters in neighboring domains. Both renormalized mean-field theory and variational Monte Carlo calculations reveal that the energies of modulated and uniform phases are very close to each other.