Nonreciprocal Terahertz Second Harmonic Generation in Superconducting NbN under Supercurrent Injection

Abstract

Giant second-harmonic generation (SHG) in the terahertz (THz) frequency range is observed in a thin film of an s-wave superconductor NbN, where the time-reversal ($\mathcal{T}$-) and space-inversion ($\mathcal{P}$-) symmetries are simultaneously broken by supercurrent injection. We demonstrate that the phase of the second-harmonic (SH) signal flips when the direction of supercurrent is inverted, i.e., the signal is ascribed to the nonreciprocal response that occurs under broken $\mathcal{P}$- and $\mathcal{T}$-symmetries. The temperature dependence of the SH signal exhibits a sharp resonance, which is accounted for by the vortex motion driven by the THz electric field in an anharmonic pinning potential. The maximum conversion ratio ${\eta }_{\mathrm{SHG}}$ reaches $\approx 10^{-2}$ in a thin film NbN with the thickness of 25 nm after the field cooling with a very small magnetic field of $\approx 1$ Oe, for a relatively weak incident THz electric field of 2.8 kV/cm at 0.48 THz.

arXiv comment6 pages, 4 figures

References in corpus (16)

• What is Nonreciprocity?
• Giant and nonreciprocal second harmonic generation from layered antiferromagnetism in bilayer CrI3
• Unidirectional spin Hall magnetoresistance in ferromagnet/normal metal bilayers
• Large Unidirectional Magnetoresistance in a Magnetic Topological Insulator
• Nonreciprocal charge transport in two-dimensional noncentrosymmetric superconductors
• Nonreciprocal current in noncentrosymmetric Rashba superconductors
• Nonreciprocal magnon propagation in a noncentrosymmetric ferromagnet
• Amplitude Higgs mode and admittance in superconductors with a moving condensate
• Discovery of Terahertz Second Harmonic Generation from Lightwave Acceleration of Symmetry--Breaking Nonlinear Supercurrents
• Infrared activation of the Higgs mode by supercurrent injection in superconducting NbN
• Nonlinear optical effects in inversion-symmetry-breaking superconductors
• Quantum and classical ratchet motions of vortices in a 2D trigonal superconductor
• Quantitative assessment of pinning forces and the superconducting gap in NbN thin films from complementary magnetic force microscopy and transport measurements
• Effect of dimensionality on the vortex-dynamics in type-II superconductor
• Current-assisted Raman activation of the Higgs mode in superconductors
• Far-infrared electrodynamics of thin superconducting NbN film in magnetic field

Cited by in corpus (37)

• Superconducting diode effect and nonreciprocal transition lines
• Milliwatt terahertz harmonic generation from topological insulator metamaterials
• Current-induced second harmonic generation in inversion-symmetric Dirac and Weyl semimetals
• Linear and Nonlinear Optical Responses in Kitaev Spin Liquids
• Nonreciprocal optical response in parity-breaking superconductors
• Nonlinear optical responses in noncentrosymmetric superconductors
• Supercurrent-induced topological phase transitions
• High-order nonlinear terahertz probing of the two-band superconductor MgB${}_2$: Third- and fifth-order harmonic generation
• Supercurrent induced resonant optical response
• Optical Manipulation of Domains in Chiral Topological Superconductors
• Nonreciprocal Meissner response in parity-mixed superconductors
• Analytical WKB theory for high-harmonic generation and its application to massive Dirac electrons
• Piezoelectric effect and diode effect in anapole and monopole superconductors
• Superconducting piezoelectric effect
• Following the Higgs mode across the BCS-BEC crossover in two dimensions
• Observation of terahertz second harmonic generation from Dirac surface states in the topological insulator Bi${}_2$Se${}_3$
• Edge-state and bulk-like laser-induced correlation effects in high-harmonic generation from a linear chain
• Photoinduced Anomalous Supercurrent Hall Effect
• Magnetic parity violation and parity-time-reversal-symmetric magnets
• Edge-state-induced correlation effects in two-color high-harmonic generation
• Direct excitation of Kelvin waves on quantized vortices
• High-harmonic generation in graphene under the application of a DC electric current: From perturbative to nonperturbative regimes
• Second-order optical response of superconductors induced by supercurrent injection
• Picosecond Trajectory of Two-dimensional Vortex Motion in FeSe${}_{0.5}$Te${}_{0.5}$ Visualized by Terahertz Second Harmonic Generation
• Nonlinear optical responses in multi-orbital topological superconductors
• Theory of nonlinear terahertz susceptibility in ferroelectrics
• Imprinting spiral Higgs waves onto superconductors with vortex beams
• Nonlinear optical responses in superconductors under magnetic fields: quantum geometry and topological superconductivity
• Microwave Microscope Studies of Trapped Vortex Dynamics in Superconductors
• Proposal for Superconducting Photodiode
• Two-color laser control of photocurrent and high harmonics in graphene
• Coupling the Higgs mode and ferromagnetic resonance in spin-split superconductors with Rashba spin-orbit coupling
• Unique properties of the optical activity in noncentrosymmetric superconductors: sum rule, missing area, and relation with the superconducting Edelstein effect
• Spatially resolved collective modes in d-wave superconductors
• Nonreciprocal Nonlinear Responses in Moving Charge Density Waves
• Temporal modulation of second harmonic generation in ferroelectrics by a pulsed electric field
• Vertex corrections to nonlinear photoinduced currents in 2D superconductors