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Updated: May 11, 2026
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Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
Periodic dynamics of fermionic superfluids in the BCS regime
1TCMP Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700064, India.
Summary
We investigated the dynamics of fermionic superfluids under periodic driving. The BCS self-consistency condition is key to understanding fermion behavior and can reveal pairing symmetries, distinguishing superfluid types.
Area of Science:
- Condensed Matter Physics
- Quantum Dynamics
- Superfluidity
Background:
- Understanding non-equilibrium dynamics in quantum systems is crucial for exploring novel states of matter.
- Fermionic superfluids, particularly in the Bardeen-Cooper-Schrieffer (BCS) limit, exhibit complex behaviors under external perturbations.
Purpose of the Study:
- To investigate the zero-temperature non-equilibrium dynamics of a fermionic superfluid subjected to a time-dependent chemical potential.
- To analyze the influence of the Bardeen-Cooper-Schrieffer (BCS) self-consistency condition on the system's long-time behavior.
- To explore how driving protocols can reveal fundamental properties of superfluids, such as pairing symmetry.
Main Methods:
- Theoretical study of a fermionic superfluid in the BCS limit under periodic driving of the chemical potential.
- Computation of fermion density, wavefunction overlap, and residual energy after multiple driving periods.
- Analytical derivation of the fermion density behavior for large driving frequencies (ω).
Main Results:
- The BCS self-consistency condition critically shapes the long-time dynamics of driven fermions.
- An analytical understanding of fermion density (n_kF) evolution after a driving period and for large ω is provided.
- The momentum distribution of generated excitations carries signatures of pairing symmetry, enabling differentiation between s-wave and d-wave superfluids.
Conclusions:
- The BCS self-consistency is essential for describing driven fermionic superfluids.
- Driving protocols offer a powerful tool to probe and distinguish different types of superfluids.
- Experimental verification of these theoretical predictions is proposed.
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