2025/11/04(Tue) 10:30 -12:00 五樓第一會議室 5F, 1st Meeting Room
Title
Resonant Inelastic X-Ray Scattering in Cuprates via Model-Based Computational Approaches
Abstract
Resonant inelastic x-ray scattering (RIXS) has made significant progress through investigations of cuprate high-temperature superconductors. Given the crucial role of momentum-dependent self-energy in cuprates, model-based computational approaches have been instrumental in advancing RIXS studies. We employ finite-size systems governed by Hubbard-type model Hamiltonians and utilize Lanczos-type exact diagonalization and the dynamical density-matrix renormalization group to compute RIXS spectra. These calculations successfully reproduce key experimental features, including the incident x-ray energy dependence of bimagnon excitations in insulating cuprates [1]. In addition, recent phenomenological calculations of charge excitations have highlighted the importance of momentum-dependent anisotropic scattering processes in the superconducting state, serving as a complementary approach to model-based methods [2]. Furthermore, using model-based computational techniques, we make theoretical predictions for time-resolved RIXS in insulating cuprates driven by electric-field pump pulses. Our results reveal characteristic temporal oscillations in the intensity of single-magnon excitations [3]. When the pump pulse is tuned to the edge of the Mott gap, where holon-doublon excitons are formed, a new magnetic signal emerges well below the single-magnon energy at specific momenta [4]. These new magnetic excitations could be experimentally confirmed with future improvements in the time and energy resolution of time-resolved RIXS.
[1] A. Singh et al., Sci. Rep. 15, 34183 (2025).
[2] J. Li et al., Phys. Rev. Res. 7, 023319 (2025).
[3] K. Tsutsui, K. Shinjo, and T. Tohyama, Phys. Rev. Lett. 126, 127404 (2021).
[4] K. Tsutsui, K. Shinjo, S. Sota, and T. Tohyama, Commun. Phys. 6, 41 (2023).
Language
演講語言 (Language): in English