Finite-temperature vibronic spectra from the split-operator thermofield coherence dynamics

Zhan Tong ZhangJi\v{r}\'i Van\'i\v{c}ek

Zhan Tong ZhangJi\v{r}\'i Van\'i\v{c}ek

Nov 2023

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摘要原文

The inclusion of temperature effects is important to properly simulate and interpret experimentally observed vibrationally resolved electronic spectra. We present a numerically exact approach for evaluating these spectra at finite temperature using the thermofield coherence dynamics. In this method, which avoids implementing an algorithm for solving the von Neumann equation for the coherence, the thermal vibrational ensemble is first mapped to a pure-state wavepacket in an augmented space, and this wavepacket is then propagated by solving the standard, zero-temperature Schr\"{o}dinger equation with the split-operator Fourier method. We show that the finite-temperature spectra obtained with the thermofield coherence dynamics in a Morse potential agree exactly with those computed by Boltzmann-averaging the spectra of individual vibrational levels. Because the split-operator thermofield dynamics on a full tensor-product grid is restricted to low-dimensional systems, we briefly discuss how the accessible dimensionality can be increased by various techniques developed for the zero-temperature split-operator Fourier method.