Theory of pseudospin resonance for multiband superconductors
arXiv:2310.11195 · doi:10.1103/PhysRevB.108.174504
Abstract
We formulate a generalized pseudospin formalism for multiband superconductors in the presence of an external perturbing electromagnetic field. Our theory naturally captures the effects of quantum band geometric quantities and is valid even for flat-band superconductors. As an interesting consequence of our theory, we show that there is an interband pairing fluctuations induced by the external field and mediated by the quantum band geometry. Surprisingly, this interband fluctuation is independent of the band gap, which can be understood from the geometric nature of such novel fluctuations. We derive the generalized equation of motion for the multiband pseudospin and the self-consistency equation. We present a formal solution to the pseudospin equation of motion in powers of the perturbing electromagnetic field. As a simple illustration of our theory, we calculate the Leggett modes for the two band case.
arXiv comment14 pages, 2 figures
References in corpus (14)
- Magic-angle graphene superlattices: a new platform for unconventional superconductivity
- Moire bands in twisted double-layer graphene
- Origin of Magic Angles in Twisted Bilayer Graphene
- Superfluidity in topologically nontrivial flat bands
- Topology-Bounded Superfluid Weight In Twisted Bilayer Graphene
- Superfluid weight and Berezinskii-Kosterlitz-Thouless transition temperature of twisted bilayer graphene
- Geometric and conventional contribution to superfluid weight in twisted bilayer graphene
- Theory of Anderson pseudospin resonance with Higgs mode in superconductors
- Phase-resolved Higgs response in superconducting cuprates
- Superconductivity, pseudogap, and phase separation in topological flat bands: a quantum Monte Carlo study
- Bound on resistivity in flat-band materials due to the quantum metric
- Quantum Metric Induced Phases in Moiré Materials
- Spectroscopic signatures of time-reversal symmetry breaking superconductivity
- Anomalous Higgs oscillations mediated by Berry curvature and quantum metric