2kF-Friedel to 4kF-Wigner oscillations in one-dimensional Fermi gases under confinement

摘要

Density oscillations of confined one-dimensional Fermi gases of contact repulsive interactions in a continuousnspace are discussed within Bethe-ansatz-based spin-density-functional theory. The results are compared againstnthe exact analytical and the exact diagonalization method. For an unpolarized system, the number of peaks in thendensity profiles is doubled, signaling the crossover of the 2kF -Friedel to 4kF-Wigner oscillations (with kF beingnthe Fermi wave vector). For both unpolarized and polarized systems, a threshold of the short-range interactionnstrength can be found where Nf -peak Wigner oscillations of a 4kF wave vector appear in the density profilen(Nf is the total particle number).