High-harmonic generation in spin-orbit coupled systems

Abstract

We study high-harmonic generation in two-dimensional electron systems with Rashba and Dresselhaus spinorbit coupling and derive harmonic generation selection rules with the help of group theory. Based on the band structures of these minimal models and explicit simulations we reveal how the spin-orbit parameters control the cutoff energy in the high-harmonic spectrum. We also show that the magnetic field and polarization dependence of this spectrum provides information on the magnitude of the Rashba and Dresselhaus spin-orbit coupling parameters. The shape of the Fermi surface can be deduced at least qualitatively and if only one type of spin-orbit coupling is present, the coupling strength can be determined.

High-harmonic generation in spin and charge current pumping at ferromagnetic or antiferromagnetic resonance in the presence of spin-orbit coupling

“…Furthermore, in two-dimensional (2D) systems breaking inversion symmetry, such as monolayer of MoS 2 [43] or surface states of topological insulators [44], additional even-order harmonics or non-integer harmonics [44] can emerge. This has inspired recent theoretical studies on possible high harmonic generation in spin currents pumped by laser light irradiating magnetic insulators [45,46] or SO-split 2D electron gases [42] (note that in the latter case, cutoff harmonic order increases linearly with the Rashba SO coupling strength, unlike our result in Fig. 4).…”

“…We anticipate that harmonics higher than n max = 4 [Fig. 4], or perhaps even non-integer harmonics, could be possible for more complex materials and their SO-split band structures [27,42] than simplistic Rashba SO coupling in 1D employed in Fig. 1 to demonstrate high-harmonic generation in spin and charge pumping from spintronic devices as a proof of principle.…”

Quantum interference and imaging using intense laser fields

“…On the contrary, in solids, the situation is rather different due to periodicity of the static potential. The possibility of electron-electron correlation effects [159,160], electron-phonon effects, spin-orbit couplings [161][162][163] and spin orders' effects [164] offer a new and extremely attractive research field for ultrafast spectroscopy and laser control. For instance, the hole can be driven by the laser as well, since the energy dispersion of valence states is not zero [154,155].…”

High‐Harmonic Generation from 2D Monolayer Electrides

“…202100368 Unlike atoms and molecules, the nonlinear condensed matter provides higher efficiency and enables us to compress the volume of experimental setup. Although HHG from condensed matter has been extensively investigated both theoretically [29][30][31][32][33][34][35][36][37][38][39] and experimentally, [40][41][42][43][44][45][46] the mechanism is still under debate due to the complicated elementary processes. In particular, two-dimensional (2D) monolayers show interesting behaviors: HHG pumped with laser pulses with in-plane polarization behaves similar to the case of solid state medium, while atomic-like HHG is observed for out-of-plane polarized pumping.…”