Two-dimensional coherent spectrum of interacting spinons from matrix-product states

Abstract

We compute numerically the second and third order nonlinear magnetic susceptibilities of an Ising ladder model in the context of two-dimensional coherent spectroscopy by using the infinite time-evolving block decimation method. The Ising ladder model couples a quantum Ising chain to a bath of polarized spins, thereby effecting the decay of spinon excitations. We show that its third order susceptibility contains a robust spinon echo signal in the weak coupling regime, which appears in the two-dimensional coherent spectrum as a highly anisotropic peak in the frequency plane. The spinon echo peak reveals the dynamical properties of the spinons. In particular, the spectral peak corresponding to the high energy spinons, which couple to the bath, is suppressed with increasing coupling, whereas those do not show no significant changes.

Nonlinear response of the Kitaev honeycomb lattice model in a weak magnetic field

“…According to this technique, one can reveal distinguishable spectroscopic characteristics of different types of gapped spin liquids 52 , signatures of interactions in many-body quantum systems [53][54][55][56][57][58] and extract different relaxation times in quantum systems with quenched disorders 59 . Very recently the 2DCS of one-dimensional Ising model has been investigated by implementing matrix-product state numerical simulations 60,61 . Nonlinear responses of KM in the context of high-harmonic generation (HHG) has been studied theoretically 62 and anomalous behavior of the Kitaev spin liquid candidate α-RuCl 3 for static nonlinear susceptibilities has also been reported 63 .…”