2025/07/23 by Wolfram Brenig, Brenig, Wolfram · 1 citation
Physics and Astronomy · Engineering · #Nonlinear Photonic Systems #Spectroscopy and Quantum Chemical Studies #Advanced Fiber Optic Sensors
paper · pdf · doi:10.48550/arxiv.2507.17823
A study of the dynamical two-dimensional (2D) nonlinear response of the dimerized spin-1/2 chain to external electric fields is presented. The coupling of the spin system to those fields is set to arise from the inverse Dzyaloshinskii-Moriya interaction. In the XY-limit, we provide analytical expressions for the second-order nonlinear dynamical response function. Apart from multi spinon continua, this response displays a strong antidiagonal, i.e. galvanoelectric, feature in the 2D frequency plane. This allows to read off scattering rates of the fractional spinon excitations. For the XXZ-case, we focus on the interaction-driven renormalization of the light-matter coupling by considering vertex corrections which are induced by the zz-exchange. We show this renormalization to modify the spinon joint density of states significantly, potentially allowing for the formation of in-gap bound states. As a result, the vertex corrected light-matter coupling can induce a dramatic spectral weight transfer to lower energies for the dynamical response function within the 2D frequency plane.