2016/11/19 by Keita Kobayashi, Yukihiro Ota, Kobayashi, Keita +7
Physics and Astronomy · #FOS: Physical sciences #Quantum Gases (cond-mat.quant-gas) #Superconductivity (cond-mat.supr-con) #cond-mat.quant-gas #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1611.06422
6 pages, 4 figures
arxiv created 2016/11/22 · arxiv updated 2016/11/23
We explore the ground states in population-imbalanced attractive 1-D fermionic optical lattice filling p orbitals over the lowest s one by using the density-matrix-renormalization-group (DMRG) method. The DMRG calculations find the occurrence of spatially non-uniform off-diagonal long-range order. In contrast to Fulde-Ferrel Larkin-Ovchinikov pair as observed in the single-band Hubbard model. The spatial oscillation period of the pair correlation function is widely fixed to be π irrespective of the mismatch between spin-split Fermi surfaces. The ground-state π order corresponds to η-pair condensate predicted by Yang [Phys. Rev. Lett. 63, 2144 (1989)]. Taking account of the effects of harmonic traps, we confirm that the η-pair state distinctly emerges at the center of the trap potential surrounded by perfectly-polarized states even in the trapped cases.