Deterministic Quantum Jump (DQJ) Method for Weakly Dissipative Systems

TL;DR

The paper introduces a deterministic quantum jump (DQJ) method that improves simulation efficiency for weakly dissipative quantum systems by eliminating stochastic sampling errors, aiding quantum technology research.

Contribution

A novel DQJ method that outperforms standard quantum jump techniques in weakly dissipative regimes, enabling more accurate and efficient simulations of open quantum systems.

Findings

Outperforms standard methods in weak dissipation regimes

Reconstructs density matrix at single and double jump levels

Demonstrated on Ising model and Kerr oscillator examples

Abstract

Physical quantum systems are generically coupled to an environment, resulting in open system dynamics. A typical approach to simulating this dynamics is to propagate the density matrix of the system via the Lindblad master equation. This approach is numerically challenging due to the size of the density matrix, which has led to the development of quantum jump methods, which unravel the density matrix into an ensemble of state vectors. These methods utilize a stochastic sampling of the quantum jump times, which becomes inefficent for weakly dissipative dynamics, in which jumps are rare events. Here, we propose the deterministic quantum jump (DQJ) method, which we show to outperform standard quantum jump methods in the weakly dissipative regime, by removing the error of stochastic sampling. We describe the methodology at the single-jump and two-jump level, reconstructing the density matrix at the corresponding level. We demonstrate the performance of the method for two examples, the dissipative transverse-field Ising model, and the dissipative Kerr oscillator. Given that quantum technologies such as quantum computing have weakly dissipative quantum dynamics as their central focus, we propose this method to be utilized in that context, for exploring and understanding quantum technology platforms.