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Maximal steady-state entanglement in autonomous quantum thermal machines

Khandelwal, Shishir LU ; Annby-Andersson, Björn LU ; Diotallevi, Giovanni Francesco LU ; Wacker, Andreas LU orcid and Tavakoli, Armin LU (2025) In npj Quantum Information 11(1).
Abstract

We devise an autonomous quantum thermal machine consisting of three pairwise-interacting qubits, two of which are locally coupled to thermal reservoirs. The machine operates autonomously, as it requires no time-coherent control, external driving or quantum bath engineering, and is instead propelled by a chemical potential bias. Under ideal conditions, we show that this out-of-equilibrium system can deterministically generate a maximally entangled steady-state between two of the qubits, or any desired pure two-qubit entangled state, emerging as a dark state of the system. We study the robustness of entanglement production with respect to several relevant parameters, obtaining nearly-maximally-entangled states well-away from the ideal... (More)

We devise an autonomous quantum thermal machine consisting of three pairwise-interacting qubits, two of which are locally coupled to thermal reservoirs. The machine operates autonomously, as it requires no time-coherent control, external driving or quantum bath engineering, and is instead propelled by a chemical potential bias. Under ideal conditions, we show that this out-of-equilibrium system can deterministically generate a maximally entangled steady-state between two of the qubits, or any desired pure two-qubit entangled state, emerging as a dark state of the system. We study the robustness of entanglement production with respect to several relevant parameters, obtaining nearly-maximally-entangled states well-away from the ideal regime of operation. Furthermore, we show that our machine architecture can be generalised to a configuration with 2n − 1 qubits, in which only a potential bias and two-body interactions are sufficient to generate genuine multipartite maximally entangled steady states in the form of a W state of n qubits.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
npj Quantum Information
volume
11
issue
1
article number
28
publisher
Nature Partner Journals
external identifiers
  • scopus:85218411741
ISSN
2056-6387
DOI
10.1038/s41534-025-00981-7
language
English
LU publication?
yes
id
6d60c73e-7310-4936-9266-85bad94e6e92
date added to LUP
2025-06-09 11:43:16
date last changed
2025-10-14 12:45:07
@article{6d60c73e-7310-4936-9266-85bad94e6e92,
  abstract     = {{<p>We devise an autonomous quantum thermal machine consisting of three pairwise-interacting qubits, two of which are locally coupled to thermal reservoirs. The machine operates autonomously, as it requires no time-coherent control, external driving or quantum bath engineering, and is instead propelled by a chemical potential bias. Under ideal conditions, we show that this out-of-equilibrium system can deterministically generate a maximally entangled steady-state between two of the qubits, or any desired pure two-qubit entangled state, emerging as a dark state of the system. We study the robustness of entanglement production with respect to several relevant parameters, obtaining nearly-maximally-entangled states well-away from the ideal regime of operation. Furthermore, we show that our machine architecture can be generalised to a configuration with 2n − 1 qubits, in which only a potential bias and two-body interactions are sufficient to generate genuine multipartite maximally entangled steady states in the form of a W state of n qubits.</p>}},
  author       = {{Khandelwal, Shishir and Annby-Andersson, Björn and Diotallevi, Giovanni Francesco and Wacker, Andreas and Tavakoli, Armin}},
  issn         = {{2056-6387}},
  language     = {{eng}},
  number       = {{1}},
  publisher    = {{Nature Partner Journals}},
  series       = {{npj Quantum Information}},
  title        = {{Maximal steady-state entanglement in autonomous quantum thermal machines}},
  url          = {{http://dx.doi.org/10.1038/s41534-025-00981-7}},
  doi          = {{10.1038/s41534-025-00981-7}},
  volume       = {{11}},
  year         = {{2025}},
}