Robust Variational Ground-State Solvers via Dissipative Quantum Feedback Models

TL;DR

This paper introduces a robust variational approach for finding ground states of open quantum systems using dissipative quantum feedback, ensuring physical realizability and stability against disturbances, with applications in quantum optics and chemistry.

Contribution

It presents a novel variational framework that leverages dissipative quantum feedback models, incorporating H-infinity control for robustness, and demonstrates compatibility with experimental quantum platforms.

Findings

Achieves convergence to a unique steady state regardless of initial conditions.

Enhances robustness against disturbances through H-infinity control.

Shows advantages over QAOA in stability and physical implementability.

Abstract

We propose a variational framework for solving ground-state problems of open quantum systems governed by quantum stochastic differential equations (QSDEs). This formulation naturally accommodates bosonic operators, as commonly encountered in quantum chemistry and quantum optics. By parameterizing a dissipative quantum optical system, we minimize its steady-state energy to approximate the ground state of a target Hamiltonian. The system converges to a unique steady state regardless of its initial condition, and the design inherently guarantees physical realizability. To enhance robustness against persistent disturbances, we incorporate H-infinity control into the system architecture. Numerical comparisons with the quantum approximate optimization algorithm (QAOA) highlight the method's structural advantages, stability, and physical implementability. This framework is compatible with experimental platforms such as cavity quantum electrodynamics (QED) and photonic crystal circuits.