Time propagation and spectroscopy of Fermionic systems using a stochastic technique

TL;DR

This paper introduces a stochastic approach for solving the time-dependent Schrödinger equation, enabling efficient ab initio calculations of electron spectra in strongly correlated fermionic systems and potential applications as a cluster solver.

Contribution

It generalizes a ground-state Quantum Monte Carlo method to time-dependent problems, improving efficiency in spectral calculations for complex systems.

Findings

Efficient real-time propagation close to the real axis

Accurate calculation of electron spectra in strongly correlated systems

Potential use as a cluster solver in embedding schemes

Abstract

We present a stochastic method for solving the time-dependent Schr\"odinger equation, generalizing a ground-state full configuration interaction Quantum Monte Carlo method. By performing the time-integration in the complex plane close to the real time axis, the numerical effort is kept manageable and the analytic continuation to real frequencies is efficient. This allows us to perform {\it ab initio} calculation of electron spectra for strongly correlated systems. The method can be used as cluster solver for embedding schemes.