Mobile magnetic impurities in a Fermi superfluid: A route to designer molecules

Sarang Gopalakrishnan, Colin V. Parker, Eugene Demler

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


A magnetic impurity in a fermionic superfluid hosts bound quasiparticle states known as Yu-Shiba-Rusinov states. We argue here that, if the impurity is mobile (i.e., has a finite mass), the impurity and its bound Yu-Shiba-Rusinov quasiparticle move together as a midgap molecule, which has an unusual "Mexican-hat" dispersion that is tunable via the fermion density. We map out the impurity dispersion, which consists of an "atomic" branch (in which the impurity is dressed by quasiparticle pairs) and a "molecular" branch (in which the impurity binds a quasiparticle). We discuss the experimental realization and detection of midgap Shiba molecules, focusing on Li-Cs mixtures, and comment on the prospects they offer for realizing exotic many-body states.

Original languageEnglish (US)
Article number045301
JournalPhysical review letters
Issue number4
StatePublished - Jan 28 2015
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


Dive into the research topics of 'Mobile magnetic impurities in a Fermi superfluid: A route to designer molecules'. Together they form a unique fingerprint.

Cite this