Superfluidity in topologically nontrivial flat bands

Tutkimustuotos: LehtiartikkeliArticleScientificvertaisarvioitu

305 Sitaatiot (Scopus)
277 Lataukset (Pure)

Abstrakti

Topological invariants built from the periodic Bloch functions characterize new phases of matter, such as topological insulators and topological superconductors. The most important topological invariant is the Chern number that explains the quantized conductance of the quantum Hall effect. Here we provide a general result for the superfluid weight Ds of a multiband superconductor that is applicable to topologically nontrivial bands with nonzero Chern number C. We find that the integral over the Brillouin-zone of the quantum metric, an invariant calculated from the Bloch functions, gives the superfluid weight in a flat band, with the bound Dsgreater than or equal to|C|. Thus, even a flat band can carry finite superfluid current, provided the Chern number is nonzero. As an example, we provide Ds for the time-reversal invariant attractive Harper–Hubbard model that can be experimentally tested in ultracold gases. In general, our results establish that a topologically nontrivial flat band is a promising concept for increasing the critical temperature of the superconducting transition.
AlkuperäiskieliEnglanti
Artikkeli8944
Sivut1-9
Sivumäärä9
JulkaisuNature Communications
Vuosikerta6
DOI - pysyväislinkit
TilaJulkaistu - 2015
OKM-julkaisutyyppiA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Tutkimusalat

  • Chern number
  • flat band
  • multiband superconductors
  • room-temperature superconductivity
  • superfluid density
  • superfluidity
  • topological invariant

Sormenjälki

Sukella tutkimusaiheisiin 'Superfluidity in topologically nontrivial flat bands'. Ne muodostavat yhdessä ainutlaatuisen sormenjäljen.

Siteeraa tätä