Unconventional fermionic pairing states in a monochromatically tilted optical lattice

TL;DR

This paper demonstrates how periodic driving in a one-dimensional attractive Fermionic Hubbard model can induce and control unconventional fermionic pairing states with finite momentum, enabling potential engineering of novel fermionic condensates.

Contribution

It introduces a method to generate and manipulate finite-momentum pairing states in fermionic systems using periodic driving and compares numerical results with Floquet theory.

Findings

Finite-momentum Cooper-pair condensates can be realized via periodic driving.

The condensate momentum is tunable by adjusting driving parameters.

Condensate can be 'frozen' by quenching parameters to specific values.

Abstract

We study the one-dimensional attractive Fermionic Hubbard model under the influence of periodic driving with the time-dependent density matrix renormalization group method. We show that the system can be driven into an unconventional pairing state characterized by a condensate made of Cooper-pairs with a finite center-of-mass momentum similar to a Fulde-Ferrell state. We obtain results both in the laboratory and the rotating reference frames demonstrating that the momentum of the condensate can be finely tuned by changing the ratio between the amplitude and the frequency of the driving. In particular, by quenching this ratio to the value corresponding to suppression of the tunnelling and the Coulomb interaction strength to zero, we are able to "freeze" the condensate. We finally study the effects of different initial conditions, and compare our numerical results to those obtained from a time-independent Floquet theory in the large frequency regime. Our work offers the possibility of engineering and controlling unconventional pairing states in fermionic condensates.