Abstract
We develop a theory to describe the dynamics of a driven-dissipative many-body Fermi system to pursue our proposal to realize exotic quantum states based on reservoir engineering. Our idea is to design the shape of a Fermi surface so as to have multiple Fermi edges by properly attaching multiple reservoirs with different chemical potentials to a fermionic system. These emerged edges give rise to additional scattering channels that can destabilize the system into unconventional states, which is exemplified in this work by considering a driven-dissipative attractively interacting Fermi gas. By formulating a quantum kinetic equation using the Nambu-Keldysh Green's function technique, we explore nonequilibrium steady states in this system and assess their stability. We find that, in addition to the Bardeen-–Cooper–-Schrieffer-type isotropic pairing state, a Fulde-Ferrell-type anisotropic superfluid state being accompanied by Cooper pairs with nonzero center-of-mass momentum exists as a stable solution, even in the absence of a magnetic Zeeman field. Our result implies a great potential of realizing quantum matter beyond the equilibrium paradigm by engineering the shape and topology of Fermi surfaces in both electronic and atomic systems.
4 More- Received 2 November 2021
- Revised 1 April 2022
- Accepted 29 June 2022
- Corrected 25 July 2022
DOI:https://doi.org/10.1103/PhysRevA.106.013311
©2022 American Physical Society
Physics Subject Headings (PhySH)
Corrections
25 July 2022
Correction: The previously published order of authors was presented incorrectly and has been fixed.