We investigate quantum entanglement between two (spin- $1∕2$ ) fermions inside a cylindrical harmonic trap, making use of the von Neumann entropy for the reduced single-particle density matrix as the pure-state entanglement measure. We explore the dependence of pair entanglement on the geometry and strength of the trap and on the strength of the pairing interaction over the complete range of the effective BCS to BEC crossover. Our result elucidates an interesting connection between our model system of two fermions and that of two interacting bosons.We investigate quantum entanglement between two (spin-$1∕2$) fermions inside a cylindrical harmonic trap, making use of the von Neumann entropy for the reduced single-particle density matrix as the pure-state entanglement measure. We explore the dependence of pair entanglement on the geometry and strength of the trap and on the strength of the pairing interaction over the complete range of the effective BCS to BEC crossover. Our result elucidates an interesting connection between our model system of two fermions and that of two interacting bosons.

arXiv:quant-ph/0701130Physical Review AJan 25, 20072 citations

Pairing in Fermion Systems

S. Mazumdar

Physical Review LettersNov 30, 19872 citations

Competing Orders in One-Dimensional Spin- 3 / 2 Fermionic Systems

Congjun Wu

Novel competing orders are found in spin-3/2 cold atomic systems in one-dimensional optical traps and lattices. In particular, the quartetting phase, a four-fermion counterpart of Cooper pairing, exists in a large portion of the phase diagram. The transition between the quartetting and singlet Cooper pairing phases is controlled by an Ising symmetry breaking in one of the spin channels. The singlet Cooper pairing phase also survives in the purely repulsive interaction regime. In addition, various charge and bond ordered phases are identified at commensurate fillings in lattice systems.Novel competing orders are found in spin-3/2 cold atomic systems in one-dimensional optical traps and lattices. In particular, the quartetting phase, a four-fermion counterpart of Cooper pairing, exists in a large portion of the phase diagram. The transition between the quartetting and singlet Cooper pairing phases is controlled by an Ising symmetry breaking in one of the spin channels. The singlet Cooper pairing phase also survives in the purely repulsive interaction regime. In addition, various charge and bond ordered phases are identified at commensurate fillings in lattice systems.

arXiv:cond-mat/0409247Physical Review LettersDec 23, 2005167 citations

Pairing interaction in finite Fermi-systems

Dieter Zawischa

The European Physical Journal AOct 1, 19723 citations

Coherent Pairing of the Second kind for Strongly Interacting Fermions

Morrel H. Cohen

Physical Review LettersJun 15, 196426 citations

Fluid-dynamical scheme for equilibrium properties of two trapped fermion species with pairing interactions

P. Capuzzi, E. Susana Hernández, L. Szybisz

We present a generalization of the fluid-dynamical scheme developed for nuclear physics to the case of two trapped fermion species with pairing interactions. To establish a macroscopic description of the mass and momentum conservation laws, we adopt a generalization of the usual Thomas-Fermi approach that includes the pairing energy. We analyze the equilibrium density and gap profiles for an equal population mixture of harmonically trapped $^{6}\mathrm{Li}$ atoms for different choices of the local equation of state. We examine slight departures from equilibrium within our formulation, finding that density oscillations can propagate as first sound coupled to pairing vibrations, that in a homogeneous fermion system exhibit a Bogoliubov-like quasiparticle spectrum. In this case, the dispersion relation for the coupled modes displays a rich scenario of stable, unstable, and damped regimes.We present a generalization of the fluid-dynamical scheme developed for nuclear physics to the case of two trapped fermion species with pairing interactions. To establish a macroscopic description of the mass and momentum conservation laws, we adopt a generalization of the usual Thomas-Fermi approach that includes the pairing energy. We analyze the equilibrium density and gap profiles for an equal population mixture of harmonically trapped $^{6}\mathrm{Li}$ atoms for different choices of the local equation of state. We examine slight departures from equilibrium within our formulation, finding that density oscillations can propagate as first sound coupled to pairing vibrations, that in a homogeneous fermion system exhibit a Bogoliubov-like quasiparticle spectrum. In this case, the dispersion relation for the coupled modes displays a rich scenario of stable, unstable, and damped regimes.

Physical Review AOct 31, 20087 citations

We investigate quantum entanglement between two (spin-

1∕2

) fermions inside a cylindrical harmonic trap, making use of the von Neumann entropy for the reduced single-particle density matrix as the pure-state entanglement measure. We explore the dependence of pair entanglement on the geometry and strength of the trap and on the strength of the pairing interaction over the complete range of the effective BCS to BEC crossover. Our result elucidates an interesting connection between our model system of two fermions and that of two interacting bosons.

^{6}\mathrm{Li}

atoms for different choices of the local equation of state. We examine slight departures from equilibrium within our formulation, finding that density oscillations can propagate as first sound coupled to pairing vibrations, that in a homogeneous fermion system exhibit a Bogoliubov-like quasiparticle spectrum. In this case, the dispersion relation for the coupled modes displays a rich scenario of stable, unstable, and damped regimes.