Interactions and Dynamics of Bosons Embedded in a Fermi Gas

Aleksej Nikolaevich Storozhenko, Peter Schuck, T. Suzuki +2 more

Propagation of a Boson-Fermion (BF) pair in a BF environment is considered. The possibility of formation of stable strongly correlated BF pairs, embedded in the continuum, is pointed out. The Fermi gas of correlated BF pairs shows a strongly modified Fermi surface. The interaction between like particles is neglected in this exploratory study. Various physical situations where our pairing mechanism could be of importance are invoked.

John E. Thomas, S. L. Hemmer, Joseph M. Kinast +3 more

Nicolás Nessi, Anı́bal Iucci, Miguel A. Cazalilla

We study the effect of suddenly turning on a long-range interaction in a spinless Fermi gas in two dimensions. The short- to intermediate-time dynamics is described using the method of bosonization of the Fermi surface. The space-time dependence of the nonequilibrium fermion density matrix as well as the evolution after the quench of the discontinuity at the Fermi momentum of the momentum distribution are computed. We find that the asymptotic state predicted by bosonization is consistent with the existence of a prethermalization plateau, which is also predicted by a perturbative approach in terms of the fermionic degrees of freedom. The bosonized representation, however, explicitly allows for the construction of the generalized Gibbs ensemble describing the prethermalized state.

Moritz Hiller, Joshua D. Bodyfelt, Tsampikos Kottos +1 more

J. Santhanam, V. M. Kenkre, V. V. Konotop

It is shown that a Bose-Fermi mixture of a degenerate gas of spin-polarized fermions, whose number significantly exceeds the number of bosons, embedded in a strongly anisotropic trap, is described by the one-dimensional coupled nonlinear Schr\"odinger equation for the boson component and the wave equation with external source for the fermion component. Depending on the type of boson-fermion interaction, the system may display modulational instability and the existence of solitons in the fermion and boson components, respectively. Such solitons represent either a local decrease (increase) of the density of both the components or a decrease of the density in one component and an increase of the density in the other component. It is shown that the type of the effective interactions can be easily managed by varying the trap geometry or by means of Feshbach resonance.

Sebastian Will