Related papers: Dynamical excitations of one-dimensional Fulde-Fer…
We describe the excitation spectrum of a two-component neutral Fermi gas in the superfluid phase at finite temperature by deriving a suitable Random-Phase approximation with the technique of functional derivatives. The obtained spectrum for…
We present a general method for obtaining the exact static solutions and collective excitation frequencies of a trapped Bose-Einstein condensate (BEC) with dipolar atomic interactions in the Thomas-Fermi regime. The method incorporates…
We propose an experiment to probe ferromagnetic phenomena in an ultracold Fermi gas, while alleviating the sensitivity to three-body loss and competing many-body instabilities. The system is initialized in a small pitch spin spiral, which…
We present an experimental investigation of the dynamic spin response of a strongly interacting Fermi gas using Bragg spectroscopy. By varying the detuning of the Bragg lasers, we show that it is possible to measure the response in the spin…
Dark solitons in quantum fluids are well known nonlinear excitations that are usually characterized by a single length scale associated with the underlying background fluid. We show that in the presence of spin-orbit coupling and a linear…
We revisit a classic study [D. S. Hall {\it et al.}, Phys. Rev. Lett. {\bf 81}, 1539 (1998)] of interpenetrating Bose-Einstein condensates in the hyperfine states $\ket{F = 1, m_f = -1}\equiv\ket{1}$ and $\ket{F = 2, m_f = +1}\equiv\ket{2}$…
Correlation functions related to the dynamic density response of the one-dimensional Bose gas in the model of Lieb and Liniger are calculated. An exact Bose-Fermi mapping is used to work in a fermionic representation with a pseudopotential…
We provide a description of the dynamic structure factor of a homogeneous unitary Fermi gas at low momentum and low frequency, based on the dissipative two-fluid hydrodynamic theory. The viscous relaxation time is estimated and is used to…
We calculate the damping of the Bogoliubov-Anderson mode in a one-dimensional two-component attractive Fermi gas for arbitrary coupling strength within a quantum hydrodynamic approach. Using the Bethe-Ansatz solution of the 1D BCS-BEC…
We study theoretically the coherent nonlinear optical response of doped semiconductors with partially occupied subbands. When the Fermi energy of an occupied subband approaches the exciton level of an upper subband, the absorption spectrum…
We analyse a Bose-Einstein condensate (BEC) mixed with a superfluid two-component Fermi gas in the whole BCS-BEC cross-over. Using a quasiparticle random phase approximation combined with Beliaev theory to describe the Fermi superfluid and…
Emergent lattices at mesoscopic length scales have evoked interest in several recent contexts, e.g., in crystalline arrangements of skyrmions. It is a challenging task to determine their collective excitations as the unit cells are large…
We calculate the effects of two-body interactions on the low frequency oscillations of a normal Fermi gas confined in a harmonic trap. The mean field contribution to the collective frequencies is evaluated in the collisionless regime using…
We study attractively interacting fermions on a square lattice with dispersion relations exhibiting strong spin-dependent anisotropy. The resulting Fermi surface mismatch suppresses the s-wave BCS-type instability, clearing the way for…
We model the one-dimension (1D) to three-dimension (3D) crossover in a cylindrically trapped Fermi gas with attractive interactions and spin-imbalance. We calculate the mean-field phase diagram, and study the relative stability of exotic…
A possibility of the condensation of excitations with a non-zero momentum in rectilinearly moving and rotating superfluid bosonic and fermionic (with Cooper pairing) media is considered in terms of a phenomenological order-parameter…
In phase transitions, spontaneous symmetry breaking results in a non-zero order parameter and two collective excitations: the Goldstone and the amplitude mode. These modes, which define key properties of superconductors and fermionic…
We consider the linear density response of a two-component (superfluid) Fermi gas of atoms when the perturbation is caused by laser light. We show that various types of laser excitation schemes can be transformed into linear density…
The spin-orbit coupled degenerate Fermi gas provides a totally new platform to realize topological superfluids and related topological excitations. Previous studies have mainly focused on the properties of the ground state. Here we consider…
Collective oscillations of superfluid mixtures of ultra cold fermionic and bosonic atoms are investigated while varying the fermion-boson scattering length. We study the dynamics with respect to excited center of mass modes and breathing…