Quantum fluctuations and vortex-antivortex unbinding in the 2D BCS-BEC crossover
arXiv:1611.00225 · doi:10.1007/s10948-016-3830-6
Abstract
Very recently quasi two-dimensional (2D) systems made of attractive fermionic alkali-metal atoms with a widely tunable interaction due to Fano-Feshbach resonances have been realized. In this way it has been achieved the 2D crossover from the Bardeen-Cooper-Schrieffer regime of weakly-interacting Cooper pairs to the Bose-Einstein condensate regime strongly bound dimers. These experiments pave the way to the investigation of 2D strongly-interacting attractive fermions during the Berezinskii-Kosterlitz-Thouless (BKT) transition from a low-temperature superfluid phase characterized by quasi-condensation to a high-temperature normal phase, where vortex proliferation driven by quantum and thermal fluctuations completely destroys superfluidity. In this paper we discuss our preliminar theoretical results on the behavior of the BKT critical temperature across the crossover. Our microscopic calculations are based on functional integration taking into account renormalized Gaussian fluctuations and the crucial 2D effect of vortex-antivortex unbinding.
4 pages, 2 figures, short version of the talk given at the International Conference "SUPERSTRIPES 2016", Ischia, June 23-29 (2016), to be published in the Proceedings
References in corpus (17)
- A Common Thread: the pairing interaction for the unconventional superconductors
- BCS-BEC Crossover: From High Temperature Superconductors to Ultracold Superfluids
- The Unitary Fermi Gas: From Monte Carlo to Density Functionals
- High Temperature Superfluidity in Double Bilayer Graphene
- Observation of the Berezinskii-Kosterlitz-Thouless Phase Transition in an Ultracold Fermi Gas
- Observation of pair condensation in the quasi-2D BEC-BCS crossover
- An exactly solvable model of the BCS-BEC crossover
- Coexistence of BCS and BEC-like pair structures in halo nuclei
- Ground-state pressure of quasi-2D Fermi and Bose gases
- Equation of State of Ultracold Fermions in the 2D BEC-BCS Crossover Region
- Superconductivity in an electron band just above the Fermi level: possible route to BCS-BEC superconductivity
- Quantum fluctuations in the BCS-BEC crossover of two-dimensional Fermi gases
- Zero-point energy of ultracold atoms
- Finite-temperature quantum fluctuations in two-dimensional Fermi superfluids
- Superfluidity, Sound Velocity and Quasi Condensation in the 2D BCS-BEC Crossover
- Composite bosons in the 2D BCS-BEC crossover from Gaussian fluctuations
- Evolution of Cooper pairs with zero-center-of-mass momentum and their first-order correlation function in a two-dimensional ultracold Fermi gas near the observed Berezinskii-Kosterlitz-Thouless transition
Cited by in corpus (5)
- Fermi-to-Bose crossover in a trapped quasi-2D gas of fermionic atoms
- Substrate mediated nitridation of niobium into superconducting Nb2N thin films for phase slip study
- Dimensional crossover in ultracold Fermi gases from Functional Renormalisation
- Pseudogap regime of a two-dimensional uniform Fermi gas
- Lattice, Charge and Spin phase inhomogeneity in complex striped quantum matter