Vortices and superfluidity in a strongly interacting Fermi gas

By M. Zwierlein, J. Abo-Shaeer, A. Schirotzek, C. Schunck, W. Ketterle. Nature, 2005

781 citations recorded by the source corpus.

Quantum degenerate Fermi gases provide a remarkable opportunity to study strongly interacting fermions. In contrast to other Fermi systems, such as superconductors, neutron stars or the quark-gluon plasma of the early Universe, these gases have low densities and their interactions can be precisely controlled over an enormous range. Previous experiments with Fermi gases have revealed condensation of fermion pairs. Although these and other studies were consistent with predictions assuming superfluidity, proof of superfluid behaviour has been elusive. Here we report observations of vortex lattices in a strongly interacting, rotating Fermi gas that provide definitive evidence for superfluidity. The interaction and therefore the pairing strength between two 6Li fermions near a Feshbach resonance can be controlled by an external magnetic field. This allows us to explore the crossover from a Bose–Einstein condensate of molecules to a Bardeen–Cooper–Schrieffer superfluid of loosely bound pairs. The crossover is associated with a new form of superfluidity that may provide insights into high-transition-temperature superconductors.

Subfields: Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/d934555c09eded819d2a9c0ef3fd5c4f530bc404

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In Atomic and Molecular Physics, and Optics

Citations in the corpus

Quantum Simulation (2013, methodology): “By tuning interatomic interactions using Feshbach resonances, it was possible to investigate the crossover from a Bardeen-Cooper-Schrieffer (BCS) state of weakly attractive fermions to a Bose-Einstein condensate (BEC) of tightly bound fermion pairs (Regal et al., 2004; Zwierlein et al., 2005).”
Feshbach resonances in ultracold gases (2008, background): “Superfluidity of a (6)Li Fermi gas in the BEC-BCS crossover was observed by (Zwierlein et al., 2005).”
Quantum turbulence in trapped atomic Bose-Einstein condensates (2015, methodology): “[234] where an array of vortices was successfully created on an ultracold gas of (6)Li particles by a stirring process, similar to this followed in ordinary BECs.”
Artificial gauge fields in materials and engineered systems (2017, neutral): “a condensed phase of atomic fermion pairs [79].”
(INVITED) Vortex solitons: Old results and new perspectives (2019, background): “Results obtained for the “dark vortices”, starting from the earliest ones [86–88], have been collected in many publications dealing with various settings in photonics [89–95] (including exciton-polariton condensates [96–98], where the vortices exist in dissipative media) and BEC [61, 99–105], as wel”
Rapidly rotating atomic gases (2008, methodology): “The formation of a lattice of quantized vortices has been demonstrated in experiments described in Ref.[216].”
Rotating trapped Bose-Einstein condensates (2008, background): “For intermediate Ω̄, a vortex lattice forms, as in Zwierlein et al. (2005).”
Quantum simulation of the Hubbard model with ultracold fermions in optical lattices (2018, positive): “In principle, this may be realized via the observation of vortices in rotating gases or by studying the response of the gas to a moving obstacle, as done for homogeneous Bose and Fermi gases [105,106,107,108].”
Stabilization of a purely dipolar quantum gas against collapse (2007, background): “The contact interaction also plays a crucial role in the physics of strongly correlated systems like in the BEC-BCS crossover [2] or in quantum phase transitions like the Mott insulator transition [3].”
Strongly correlated quantum fluids: ultracold quantum gases, quantum chromodynamic plasmas and holographic duality (2012, background): “The observation of a vortex lattice in 2005 provided direct verification of Fermi superfluid behavior [59].”