Current-enabled optical conductivity of superconductors

Abstract

In most superconductors, optical excitations require impurity scattering or the presence of multiple bands. This is because in clean single-band superconductors, the combination of particle-hole and inversion symmetries prevents momentum-conserving transitions. In this work we show how the flow of supercurrent can lead to new contributions to optical conductivity. As supercurrent breaks inversion symmetry, transitions across the superconducting gap become allowed even in clean superconductors and dominate over impurity-induced contributions for energies comparable to the gap width. The response is dependent on the nature of the underlying normal state as well as on the type of superconducting order. Through use of the screening supercurrent with controllable magnitude and direction, that arises from an external magnetic field, this enables a detailed investigation of the superconducting state and possible gap symmetry determination in unconventional superconductors for which other techniques have not been practicable.

6+5 pages, 4+2 figures

References in corpus (9)

• Electrodynamics of Correlated Electron Materials
• Superconducting properties and Hall Effect of epitaxial NbN thin films
• Discovery of segmented Fermi surface induced by Cooper pair momentum
• Amplitude Higgs mode and admittance in superconductors with a moving condensate
• Current-induced second harmonic generation in inversion-symmetric Dirac and Weyl semimetals
• Theory of optical responses in clean multi-band superconductors
• Optical Conductivity From Pair Density Waves
• Supercurrent-induced topological phase transitions
• BCS $d$-wave behavior in the THz electrodynamic response of electron-doped cuprate superconductors

Cited by in corpus (15)

• Photoinduced Anomalous Supercurrent Hall Effect
• The Higgs-Amplitude mode in the optical conductivity in the presence of a supercurrent: Gauge-invariant formulation with disorder
• Second-order optical response of superconductors induced by supercurrent injection
• Nonlinear optical responses in multi-orbital topological superconductors
• Long-lived Higgs modes in strongly correlated condensates
• Nonlinear optical responses in superconductors under magnetic fields: quantum geometry and topological superconductivity
• Proposal for Superconducting Photodiode
• Revisiting electromagnetic response of superconductors in mean-field approximation
• Reducing the frequency of the Higgs mode in a helical superconductor coupled to an LC-circuit
• Vertex correction for the linear and nonlinear optical responses in superconductors: multiband effect and topological superconductivity
• Optical absorption activated by an ultrashort half-cycle pulse in metallic and superconducting states of the Hubbard model
• Nonreciprocal Nonlinear Responses in Moving Charge Density Waves
• Landau levels and optical conductivity in the mixed state of a generic Weyl superconductor
• Vertex corrections to nonlinear photoinduced currents in 2D superconductors
• Supercurrent effect in a charge density wave intertwined superconductor