Investigating a Quantum-Inspired Method for Quantum Dynamics

TL;DR

This paper introduces a quantum-inspired classical simulation method that reduces sampling overhead and extends the simulation of quantum many-body dynamics by exploiting causal structures and projective measurements.

Contribution

It extends quantum algorithm frameworks to simulate real-time quantum dynamics more efficiently, enabling longer simulations and better analysis of entanglement.

Findings

Reduces sampling overhead compared to existing methods

Enables longer time evolution simulations per resource

Provides efficient computation of local observables and correlations

Abstract

Building on recent advances in quantum algorithms which measure and reuse qubits and in efficient classical simulation leveraging projective measurements, we extend these frameworks to real-time dynamics of quantum many-body systems undergoing discrete-time and continuous-time Hamiltonian evolution, and find improvements that significantly reduce sampling overhead. The approach exploits causal light-cone structure by interleaving time and space evolution and applying projective measurements as soon as local subsystems reach the target physical time, suppressing entanglement growth. Comparing to time-evolving block decimation, the method reaches longer times per sample for the same resources. We also gain the ability to study dynamics of entanglement that would be occurring on quantum hardware when following similar protocols, such as the holographic quantum dynamics simulation framework. We show how to efficiently obtain local observables as well as equal-time and time-dependent correlation functions. Our findings show how optimizations for quantum hardware can benefit classical tensor network simulations and how such classical methods can yield insights into the utility of quantum simulations.