Optical response of the Leggett mode in multiband superconductors in the linear response regime
arXiv:2111.12318 · doi:10.1103/PhysRevB.105.094520
Abstract
We study optical responses of Leggett modes in multiband superconductors in the linear response regime. The Leggett mode is a collective mode unique to multiband superconductors that arises from relative phase fluctuations of superconducting orders for different bands. We use the Ginzburg-Landau (GL) description to study the collective modes in multiband systems. We find that multiband superconductors generally allow a linear coupling between the Leggett mode and external electric fields due to the presence of a cross term between different components of superconducting orders in the GL theory. The presence of a linear coupling for the Leggett mode is in sharp contrast with the absence of that for Higgs (amplitude) modes in single-band superconductors that only support nonlinear optical responses such as third harmonic generation (THG). We further confirm such a linear coupling in multiband superconductors by a more microscopic description based on a diagrammatic approach. We study the collective modes within the random phase approximation (RPA) and compute their contribution to the linear optical conductivity. These findings suggest a new route to observe the Leggett mode by optical absorption.
arXiv comment13 pages, 4 figures
References in corpus (35)
- Higgs Amplitude Mode in BCS Superconductors NbTiN induced by Terahertz Pulse Excitation
- Amplitude / Higgs Modes in Condensed Matter Physics
- Field-induced superconducting phase of FeSe in the BCS-BEC cross-over
- Higgs Mode in Superconductors
- Theoretical aspects of Andreev spectroscopy and tunneling spectroscopy in non-centrosymmetric superconductors: a topical review
- Theory of Anderson pseudospin resonance with Higgs mode in superconductors
- Amplitude `Higgs' mode in 2H-NbSe2 Superconductor
- Non-linear optical effects and third-harmonic generation in superconductors: Cooper-pairs vs Higgs mode contribution
- Nonreciprocal charge transport in two-dimensional noncentrosymmetric superconductors
- Observation of Leggett's collective mode in a multi-band MgB2 superconductor
- Shallow pockets and very strong coupling superconductivity in FeSe_xTe_1-x
- Phase-resolved Higgs response in superconducting cuprates
- Higgs mode in the d-wave superconductor Bi2Sr2CaCu2O8+x driven by an intense terahertz pulse
- Nonreciprocal current in noncentrosymmetric Rashba superconductors
- Coupling of Higgs and Leggett modes in nonequilibrium superconductors
- Direct observation of Higgs mode oscillations in the pump-probe photoemission spectra of electron-phonon mediated superconductors
- Superconductivity in an electron band just above the Fermi level: possible route to BCS-BEC superconductivity
- Intrinsic Josephson effect and nonequilibrium soliton structures in two-gap superconductors
- Nonlinear electromagnetic response and Higgs mode excitation in BCS superconductors with impurities
- Classification and characterization of nonequilibrium Higgs modes in unconventional superconductors
- Nonlinear optical response of collective modes in multiband superconductors assisted by nonmagnetic impurities
- Leggett modes in iron-based superconductors as a probe of Time Reversal Symmetry Breaking
- Theory of light-induced resonances with collective Higgs and Leggett modes in multiband superconductors
- Signature of the Leggett mode in the A1g Raman response: from MgB2 to iron-based superconductors
- Nonlinear optical effects in inversion-symmetry-breaking superconductors
- Collective modes in superconductors with competing s- and d-wave interactions
- Theory of Raman response in a superconductor with extended s-wave symmetry: Application to Fe-pnictides
- Collective modes in multiband superfluids and superconductors: Multiple dynamical classes
- Quasiclassical Theory on Third-Harmonic Generation in Conventional Superconductors with Paramagnetic Impurities
- Coherent current states in a two-band superconductor
- Conservation laws, vertex corrections, and screening in Raman spectroscopy
- Collective modes in multiband superconductors: Raman scattering in iron selenides
- Leggett mode in a strong-coupling model of iron arsenide superconductors
- Leggett modes and the Anderson-Higgs mechanism in superconductors without inversion symmetry
- Identifying the dominant pairing interaction in high- FeSe superconductors through Leggett modes
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- Classification of Lifshitz invariant in multiband superconductors: an application to Leggett modes in the linear response regime in Kagome lattice models
- Linear spectroscopy of collective modes and the gap structure in two-dimensional superconductors
- Optically active Higgs and Leggett modes in multiband pair-density-wave superconductors with Lifshitz invariant
- Vertex correction for the linear and nonlinear optical responses in superconductors: multiband effect and topological superconductivity
- Reducing the frequency of the Higgs mode in a helical superconductor coupled to an LC-circuit
- Amplitude, phase, and topological fluctuations shaping the complex phase diagram of two-dimensional superconductors
- Two-dimensional coherent spectroscopy of disordered superconductors in the narrow-band and broad-band limits
- Phenomenological Ginzburg-Landau theory for triple-Q magnetic orders on a hexagonal lattice
- Landau levels and optical conductivity in the mixed state of a generic Weyl superconductor
- Raman response of collective modes in multicomponent superconductors