A thermodynamic approach to optimization in complex quantum systems

Imparato, Alberto; Chancellor, Nicholas; De Chiara, Gabriele

Abstract

We consider the problem of finding the energy minimum of a complex quantum Hamiltonian by employing a non-Markovian bath prepared in a low energy state. The energy minimization problem is thus turned into a thermodynamic cooling protocol in which we repeatedly put the system of interest in contact with a colder auxiliary system. By tuning the internal parameters of the bath, we show that the optimal cooling is obtained in a regime where the bath exhibits a quantum phase transition in the thermodynamic limit. This result highlights the importance of collective effects in thermodynamic devices. We furthermore introduce a two-step protocol that combines the interaction with the bath with a measure of its energy. While this protocol does not destroy coherence in the system of interest, we show that it can further enhance the cooling effect.

Citation

Imparato, A., Chancellor, N., & De Chiara, G. (2024). A thermodynamic approach to optimization in complex quantum systems. Quantum Science and Technology, 9(2), Article 025011. https://doi.org/10.1088/2058-9565/ad26b3

• Journal Article Type: Article
• Acceptance Date: Feb 6, 2024
• Online Publication Date: Feb 16, 2024
• Publication Date: 2024-04
• Deposit Date: Mar 13, 2024
• Publicly Available Date: Mar 13, 2024
• Journal: Quantum Science and Technology
• Electronic ISSN: 2058-9565
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 2
• Article Number: 025011
• DOI: https://doi.org/10.1088/2058-9565/ad26b3
• Keywords: optimization, quantum thermodynamics, open quantum systems
• Public URL: https://durham-repository.worktribe.com/output/2258051