English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We demonstrate the existence of a collective excitation branch in thepair-breaking continuum of superfluid Fermi gases and BCS superconductors. Atzero temperature, we analytically continue the equation on the collective modeenergy in Anderson's Random Phase Approximation or Gaussian fluctuationsthrough its branch cut associated with the continuum, and obtain the fullcomplex dispersion relation, including in the strong coupling regime. Thebranch exists as long as the chemical potential $\mu$ is positive and the wavenumber below $\sqrt{2m\mu}/\hbar$ (with m the fermion mass). In the longwavelength limit, the branch varies quadratically with the wave number, with acomplex effective mass that we compute analytically for an arbitraryinteraction strength.

Pair-Breaking Collective Branch in BCS Superconductors and Superfluid Fermi Gases