We propose a non-perturbative numerical approach to calculate the spectrum of a many-body Hamiltonian with time and momentum resolution by exactly recreating a scattering event using the time-dependent Schrödinger equation. Akin an actual inelastic scattering experiment, we explicitly account for the incident and scattered particles ( e.g. photons, neutrons, electrons...) in the Hamiltonian and obtain the spectrum by measuring the energy and momentum lost by the particle after interacting with the sample. We illustrate the method by calculating the spin excitations of a Mott-insulating Hubbard chain after a sudden quench with the aid of the time-dependent density matrix renormalization group (tDMRG) method. Our formalism can be applied to different forms of spectroscopies, such as neutron and Compton scattering, and electron energy-loss spectroscopy (EELS), for instance.
X-ray magnetic circular dichroism and resonant inelastic X-ray scattering explained: role of many-body correlation and valence fluctuations
Seoul National University（首尔大学）；Institute for Basic Science（基础科学研究院）；SLAC National Accelerator Laboratory（斯坦福直线加速器国家实验室）；Fudan University（复旦大学）；University of California, Davis（加州大学戴维斯分校）；University of Illinois（伊利诺伊大学）；National Institute of Standards and Technology（美国国家标准与技术研究院）
Excitations in a quantum spin liquid with random bonds
本文报道了两种键无序准二维量子磁体（C $_4$ H $_12$ N $_2$）Cu $_2$（Cl $_{1-x}$ Br $_x$）$_6$（x=0.035和0.075）的非弹性中子散射研究结果.与x=0样品相比，我们观察到自旋能隙增大，磁振子带宽减小，磁振子寿命缩短。额外的磁振子阻尼观察到在较高的能量远离区中心，这是发现遵循单粒子态的密度。
Resonant Raman Scattering by Charge Density and Single Particle Excitations in Semiconductor Nanostructures: A Generalized Interband-Resonant Random-Phase-Approximation Theory
