Analabha Roy, Raka Dasgupta, Sanhita Modak, Arnab Das, K. Sengupta
We study the non-equilibrium dynamics of a fermionic superfluid in the BCS limit and in the presence of a drive leading to a time dependent chemical potential $\mu(t)$. We choose a periodic driving protocol characterized by a frequency $\omega$ and compute the fermion density, the wavefunction overlap, and the residual energy of the system at the end of $n$ periods of the drive. We demonstrate that the BCS self-consistency condition is crucial in shaping the long-time behavior of the fermions subjected to the drive and provide an analytical understanding of the behavior of the fermion density $n_{k_F}$ (where $k_F$ is the Fermi momentum) after a drive period and for large $\omega$. We also show that the momentum distribution of the excitations generated due to such a drive bears the signature of the pairing symmetry and can be used, for example, to distinguish between s- and d-wave superfluids. We propose experiments to test our theory.
View original:
http://arxiv.org/abs/1209.4144
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