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One-particle density matrix of a one-dimensional Fermi gas with strong interaction

Alexander A. Ovchinnikov, Anton Vladimirovich Zabrodin

Physics Letters ADec 1, 19903 citations

Ground-state properties of a one-dimensional strongly interacting Bose-Fermi mixture in a double-well potential

Karlo Lelas, Dario Jukić, Hrvoje Buljan

We calculate the reduced single-particle density matrix (RSPDM), momentum distribution, natural orbitals and their occupancies, for a strongly repulsive one-dimensional Bose-Fermi mixture in a double-well potential with a large central barrier. We assume that all particles have the same mass, and fermions are spin polarized. For mesoscopic systems, we find that the ground-state properties qualitatively differ for mixtures with even number of particles (both odd-odd and even-even mixtures) in comparison to mixtures with odd particle numbers (odd-even and even-odd mixtures). For even mixtures the momentum distribution is smooth, whereas the momentum distribution of odd mixtures possesses distinct modulations; the differences are observed also in the off-diagonal correlations of the RSPDM, and in the occupancies of natural orbitals. The calculation is based on a formula which enables efficient calculation of the RSPDM for mesoscopic mixtures in various potentials.We calculate the reduced single-particle density matrix (RSPDM), momentum distribution, natural orbitals and their occupancies, for a strongly repulsive one-dimensional Bose-Fermi mixture in a double-well potential with a large central barrier. We assume that all particles have the same mass, and fermions are spin polarized. For mesoscopic systems, we find that the ground-state properties qualitatively differ for mixtures with even number of particles (both odd-odd and even-even mixtures) in comparison to mixtures with odd particle numbers (odd-even and even-odd mixtures). For even mixtures the momentum distribution is smooth, whereas the momentum distribution of odd mixtures possesses distinct modulations; the differences are observed also in the off-diagonal correlations of the RSPDM, and in the occupancies of natural orbitals. The calculation is based on a formula which enables efficient calculation of the RSPDM for mesoscopic mixtures in various potentials.

arXiv:0907.4580Physical Review ANov 19, 200912 citations

Parametric generation of density and spin modes with formation of stationary condensed states in ultracold two-component quasi-one-dimensional Fermi gases

Yu. Kagan, L. A. Manakova

The temporal evolution of parametrically created collective excitations is studied in an ultracold two-component atomic Fermi gas. We consider quasi-one-dimensional geometry with a permanent modulation of the transverse trap frequency leading to the generation of longitudinal modes for both density and spin branches. After involvement of the interaction between excitations, the evolution comes to the formation of the stationary state with macroscopic filling of a single density or spin mode and zero occupancy for other modes located within the parametric energy interval. In the presence of this state correlation properties of fermions change essentially. Analysis of one-particle density matrix and density-density correlators reveals possibilities for experimental study of density and spin branches.The temporal evolution of parametrically created collective excitations is studied in an ultracold two-component atomic Fermi gas. We consider quasi-one-dimensional geometry with a permanent modulation of the transverse trap frequency leading to the generation of longitudinal modes for both density and spin branches. After involvement of the interaction between excitations, the evolution comes to the formation of the stationary state with macroscopic filling of a single density or spin mode and zero occupancy for other modes located within the parametric energy interval. In the presence of this state correlation properties of fermions change essentially. Analysis of one-particle density matrix and density-density correlators reveals possibilities for experimental study of density and spin branches.

Physical Review AAug 28, 20098 citations

THE DENSITY MATRIX FOR THE SYSTEM OF NONINTERACTING FERMIONS

Yu. N. Demkov, Igor V. Komarov

Jan 1, 19650 citations

Eigenvalues of fermion density matrices

不可止佐々木

Jan 1, 19640 citations

Separation of spin and charge in cold Fermi gases

Corinna Kollath

One of the key features of one-dimensional systems is the phenomenon of spin–charge separation. We show this separation of spin and charge in real time in the 1D Hubbard model by the application of the adaptive time-dependent density-matrix renormalization group method. It is found for single particle excitations and density wave packets far beyond the low-energy Luttinger liquid theory. An experimental set-up is proposed on how to observe the spin–charge separation with ultracold Fermi gases in a harmonic trap using the presence of the Mott-insulator region. Quantitative estimates for experimental parameters are given.One of the key features of one-dimensional systems is the phenomenon of spin–charge separation. We show this separation of spin and charge in real time in the 1D Hubbard model by the application of the adaptive time-dependent density-matrix renormalization group method. It is found for single particle excitations and density wave packets far beyond the low-energy Luttinger liquid theory. An experimental set-up is proposed on how to observe the spin–charge separation with ultracold Fermi gases in a harmonic trap using the presence of the Mott-insulator region. Quantitative estimates for experimental parameters are given.

Journal of Physics B Atomic Molecular and Optical PhysicsMay 2, 20067 citations

Single-particle density matrix of a one-dimensional system of spin 1/2 Fermi particles

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