Fulde-Ferrell-Larkin-Ovchinnikov pairing states of a polarized dipolar Fermi gas trapped in a one-dimensional optical lattice

Abstract

We study the interplay between the long-and short-range interaction of a one-dimensional optical lattice system of two-component dipolar fermions by using the density matrix renormalization group method. The atomic density profile, pairing-pairing correlation function, and the compressibility are calculated in the ground state, from which we identify the parameter region of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) pairing state, half-metal (HM) state, FFLO-HM state, and the normal polarized state, and thus the phase diagram in the coordinates of the long-and short-range interaction strength. The effect of the long-range dipolar interaction on the FFLO state is discussed in details. We find that the long-range part of the dipole-dipole interaction does not sweep away the FFLO superconducting region that is driven by the short-range interaction in the Hubbard model, and thus the FFLO state survives in the wide parameter space of the long-range interaction, polarization, and filling.

Atomic Quantum Technologies for Quantum Matter and Fundamental Physics Applications

“…As for Rydbergs, these dipolar gases can be confined as well in optical lattices, traps and cavities, benefiting from the technological control achieved in those platforms. Since they have been envisioned [182], dipolar gases have been associated to a number of intriguing quantum states, such as Wigner crystals [183,184], ferrofluids [185], systems with roton-maxon excitations [186], checkerboard supersolids [187], Haldane insulators [188], the emergence of quantum scars [189], and Fulde-Ferrell-Larkin-Ovchinnikov phases [190]. These states emerge due to the interplay between quantum fluctuations and frustration effects due to interactions.…”

Spin-imbalanced ultracold Fermi gases in a two-dimensional array of tubes

“…Although several previous theoretical works [22,43,44, have calculated the phase diagram of spinimbalanced fermions in different scenarios, new calculations are needed to directly compare with the recent measurements [41]. Researchers have calculated the phase diagram in the limit of uncoupled 1D tubes using exact methods like Bethe ansatz [43,44,[52][53][54][55]84], DMRG [60,[62][63][64] and Quantum Monte Carlo [61], as well as approximate methods like MF theory [57][58][59]. While exact methods like Quantum Monte Carlo are sometimes used for calculating the phase diagram in higher dimensions too [80], MF theory is the commonly used method, which researchers have used to calculate the phase diagram for a 2D gas [50,74,81], a 3D gas with no lattice [6,7,9,[70][71][72][73], a 3D gas with a 3D lattice [65][66][67][68][69], and in the polaron limit of large spin imbalance [22,74].…”