Cascade of Solitonic Excitations in a Superfluid Fermi gas: From Planar Solitons to Vortex Rings and Lines

• Main Authors: Ku, Mark J. H (Author), Mukherjee, Biswaroop (Contributor), Yefsah, Tarik (Contributor), Zwierlein, Martin Wolfram (Contributor), Ku, Mark J. H. (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Research Laboratory of Electronics (Contributor), MIT-Harvard Center for Ultracold Atoms (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2016-02-02T15:40:11Z.
• Subjects: Article
• Online Access: Get fulltext

We follow the time evolution of a superfluid Fermi gas of resonantly interacting [superscript 6]Li atoms after a phase imprint. Via tomographic imaging, we observe the formation of a planar dark soliton, its subsequent snaking, and its decay into a vortex ring, which, in turn, breaks to finally leave behind a single solitonic vortex. In intermediate stages, we find evidence for an exotic structure resembling the Φ soliton, a combination of a vortex ring and a vortex line. Direct imaging of the nodal surface reveals its undulation dynamics and its decay via the puncture of the initial soliton plane. The observed evolution of the nodal surface represents dynamics beyond superfluid hydrodynamics, calling for a microscopic description of unitary fermionic superfluids out of equilibrium.
National Science Foundation (U.S.)
United States. Army Research Office. Multidisciplinary University Research Initiative on Atomtronics
United States. Air Force Office of Scientific Research. Presidential Early Career Award for Scientists and Engineers
United States. Air Force Office of Scientific Research. Multidisciplinary University Research Initiative on Exotic Phases
David & Lucile Packard Foundation