2026-09-23T20:22:58Zhttps://api.repository.cam.ac.uk/server/oai/requestoai:www.repository.cam.ac.uk:1810/3191392023-12-22T13:34:40Zcom_1810_198332com_1810_256064col_1810_214775
Communal pairing in Fermi gases with attractive interactions
10.17863/CAM.66258
Foo, Darryl
0000000175651383
Conduit, Gareth
0000000338076361
Weak attractive interactions in a spin-balanced fermion gas are known to induce a Cooper pairing instability
where the fermion pairs have zero net momentum, leading to BCS superconductivity. Extensions
for spin-imbalanced systems include breached superfluids, Fulde–Ferrell–Larkin–Ovchinnikov theory,
and pair density wave theory. We propose a further extension of a superconducting state, dubbed a
communal pairing state, whose underlying components are superpositions of Cooper pairs that share
minority-spin fermions. This state includes correlations between all available fermions on both Fermi
surfaces and is shown to be energetically favourable to the Fulde-Ferrell-Larkin-Ovchinnikov state.
Our numerical quantum Monte Carlo study of finite spin-imbalanced systems provides clear evidence
of the existence of such exotic pairing states. In spin-balanced systems, temporal fluctuations of
the order parameter promote communal pairing, leading to a widening in momentum space of the
superconducting gap and a decrease of the chemical potential.
University of Cambridge
2020-08-01
Thesis
Doctoral
Doctor of Philosophy (PhD)
eng
https://www.repository.cam.ac.uk/handle/1810/319139
https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/86554453-a8cd-4eb7-b2e1-198c166cfe29/download
e51838782431a263a89773b1eae7dcc5
https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/35a6a96e-4563-41cb-b1db-267c3c851657/download
353adac0d1ebdfd65ab16480263c3c87
https://creativecommons.org/licenses/by/4.0/
Superconductors
Fermi gases
Computational physics