Time-dependent fluctuating local field approach for description of the correlated fermions dynamics

TL;DR

The paper introduces a time-dependent fluctuating local field method for simulating correlated fermion dynamics, offering improved accuracy and efficiency over traditional mean-field approaches.

Contribution

It extends the stationary FLF approach to a dynamic context, enabling efficient simulation of driven correlated systems with high accuracy.

Findings

TD-FLF outperforms mean-field theory in accuracy.

It captures oscillation frequencies and amplitudes well.

The method is computationally efficient and flexible.

Abstract

We formulate a time-dependent Fluctuating Local Field (TD-FLF) method for correlated fermion dynamics, extending the stationary FLF approach. The wavefunction is approximated as an ensemble of non-interacting states subject to a classical fluctuating field, with dynamics encoded in the field's time-dependent distribution. This reduces the time-dependent Schr\"odinger equation to a generalized eigenvalue problem in a significantly reduced basis. Applied to half-filled 2D Hubbard lattices, TD-FLF yields highly accurate results, outperforming mean-field theory and capturing oscillation frequencies and amplitudes in good agreement with exact diagonalization. Its low computational cost and flexibility make TD-FLF a promising tool for simulating driven correlated systems.