Traveling Dark Solitons in Superfluid Fermi Gases

Abstract

Families of dark solitons exist in superfluid Fermi gases. The energy-velocity dispersion and number of depleted particles completely determines the dynamics of dark solitons on a slowly-varying background density. For the unitary Fermi gas we determine these relations from general scaling arguments and conservation of local particle number. We find solitons to oscillate sinusoidally at the trap frequency reduced by a factor of $1/\sqrt{3}$. Numerical integration of the time-dependent Bogoliubov-de Gennes equation determines spatial profiles and soliton dispersion relations across the BEC-BCS crossover and proves consistent with the scaling relations at unitarity.

Small changes in response to referee's comments; fig 1 revised and refs updated. Cross listed to nucl-th due to interest in the unitary Fermi gas

References in corpus (6)

• Theory of ultracold Fermi gases
• Oscillations and interactions of dark and dark-bright solitons in Bose-Einstein condensates
• Experimental observation of oscillating and interacting matter wave dark solitons
• Formation of Quantum Shock Waves by Merging and Splitting Bose-Einstein Condensates
• Larkin-Ovchinnikov state in resonant Fermi gas
• Bragg scattering of Cooper pairs in an ultra-cold Fermi gas

Cited by in corpus (5)

• Chladni solitons and the onset of the snaking instability for dark solitons in confined superfluids
• Many-Body Quantum Dynamics in the Decay of Bent Dark Solitons of Bose-Einstein Condensates
• The Snake Instability of Ring Dark Solitons in Toroidally Trapped Bose-Einstein Condensates
• Soliton-induced Majorana fermions in a one-dimensional atomic topological superfluid
• Proper phase imprinting method for a dark soliton excitation in a superfluid Fermi mixture