Post-doctoral fellow in Autonomous Quantum Thermodynamics

• PROJECT AND RESEARCH AREA

Autonomous quantum devices - devices that do not require the external control of a conventional agent or auxiliary system - are particularly promising for various applications linked to quantum technologies [1].This is notably the type of device recently developed using quantum circuits to reset a qubit [2].

In this context, a recent paper [3] introduces a thermodynamic formalism for designing autonomous quantum devices that exploit resources (in the form of non-thermal characteristics) contained in arbitrary quantum systems.As an illustrative application, an autonomous quantum refrigerator can be designed, composed solely of a qubit and a quantum harmonic oscillator (e.g. a cavity mode). When the harmonic oscillator initially contains a well-chosen non-thermal resource, their interaction is enough to cool the qubit and reduce its entropy without the need for thermal baths or external controls. This is impossible without non-thermal resources (unless, of course, the harmonic oscillator is initially colder than the qubit).

• MISSIONS AND ACTIVITIES

The overall aim of the postdoctoral fellowship is to understand and explore the possibilities and limits of such autonomous quantum devices and to foster experimental implementations. The successful candidate will work on some of the following aspects:

1. Optimisation of autonomous quantum devices. Study performance limits (maximum cooling power, maximum efficiency, maximum speed) and ways of achieving them.
2. Quantum thermodynamic theorems.
3. Implementation of quantum gates using fewer resources
4. Autonomous work extraction
5. When developing theoretical tools, methods and models, practical experimental applications will be a constant concern. Results can be tested and used on some of the following experimental platforms: nuclear magnetic resonance (NMR), NV centres, cold atom platforms (BEC, Rydberg atoms) and quantum circuits.

Project-related collaborations: Dominique Sugny (ICB Lab), Cyril Elouard (Lorraine University).

References:

[1] J. A. M. Guzmán, P. Erker, S. Gasparinetti, M. Huber, and N. Y. Halpern, DiVincenzo‐like criteria for

autonomous quantum machines, arXiv (2023), 2307.08739.

[2] M. A. Aamir, P. J. Suria, J. A. M. Guzmán, C. Castillo‐Moreno, J. M. Epstein, N. Y. Halpern, and S.

Gasparinetti, Thermally driven quantum refrigerator autonomously resets superconducting qubit, arXiv

(2023), 2305.16710.

[3] C. Elouard and C. Lombard Latune, Extending the Laws of Thermodynamics for Arbitrary Autonomous

Quantum Systems, PRX Quantum 4, 020309 (2023).