Snake instability of dark solitons in fermionic superfluids
Authors: Cetoli A., Brand, J., Scott R.G., Dalfovo F., Pitaevskii L.P.
Autors Affiliation: New Zealand Institute for Advanced Study and Centre for Theoretical Chemistry and Physics, Massey University, Private Bag 102904 NSMC, Auckland 0745, New Zealand; INO-CNR BEC Center and Dipartimento di Fisica, Universita di Trento, Via Sommarive 14, I-38123 Povo, Italy; Kapitza Institute for Physical Problems, ulica Kosygina 2, 119334 Moscow, Russia
Abstract: We present numerical calculations of the snake instability in a Fermi superfluid within the Bogoliubov-de Gennes theory of the Bose-Einstein condensate (BEC) to BCS crossover using the random-phase approximation complemented by time-dependent simulations. We examine the snaking behavior across the crossover and quantify the time scale and length scale of the instability. While the dynamics shows extensive snaking before eventually producing vortices and sound on the BEC side of the crossover, the snaking dynamics is preempted by decay into sound due to pair breaking in the deep BCS regime. At the unitarity limit, hydrodynamic arguments allow us to link the rate of snaking to the experimentally observable ratio of inertial to physical mass of the soliton. In this limit we witness an unresolved discrepancy between our numerical estimates for the critical wave number of suppression of the snake instability and recent experimental observations with an ultracold Fermi gas.
Journal/Review: PHYSICAL REVIEW A
Volume: 88 (4) Pages from: 043639 to: 043639
More Information: We thank Sandro Stringari and Martin Zwierlein for insightful discussions. A. C. is grateful to the Wenner-Gren foundations for financial support. The work was also supported by the ERC through the QGBE grant, the Provincia Autonoma di Trento, the Italian MIUR under Contract Cofin-2009 \”Quantum gases beyond equilibrium\”, and the Marsden Fund of New Zealand under contract MAU0910. R.S. is grateful for the use of the AURORA supercomputing facilities in Trento.DOI: 10.1103/PhysRevA.88.043639Citations: 34data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-08-09References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here