论文标题
超越扰动理论：一种与弹性散射光谱的时间有关的方法，远离平衡
Beyond perturbation theory: A time-dependent approach to inelastic scattering spectroscopies in- and away from equilibrium
论文作者
论文摘要
我们提出了一种非扰动数值方法，通过使用时间依赖性的schrödinger方程来精确地重新创建散射事件，从而计算多体哈密顿量的频谱，并分辨时间和动量。相对于实际的非弹性散射实验，我们明确地说明了哈密顿量中的入射颗粒（例如光子，中子，电子...），并通过测量与样品相互作用后粒子损失的能量和动量来获得光谱。我们通过计算借助时间依赖性密度矩阵重新归一化组（TDMRG）方法在突然淬灭后，通过计算莫特构造哈伯德链的自旋激发来说明了该方法。例如，我们的形式主义可以应用于不同形式的光谱镜，例如中子和康普顿散射，以及电子损失光谱法（EELS）。
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.
