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arXiv · 2009.13657

Relaxation to Equilibrium in a Quantum Network

Jaroslav Novotný·Angelo Mariano·Saverio Pascazio·Antonello Scardicchio·Igor Jex
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Abstract

The approach to equilibrium of quantum mechanical systems is a topic as old as quantum mechanics itself, but has recently seen a surge of interest due to applications in quantum technologies, including, but not limited to, quantum computation and sensing. The mechanisms by which a quantum system approaches its long-time, limiting stationary state are fascinating and, sometimes, quite different from their classical counterparts. In this respect, quantum networks represent a mesoscopic quantum systems of interest. In such a case, the graph encodes the elementary quantum systems (say qubits) at its vertices, while the links define the interactions between them. We study here the relaxation to equilibrium for a fully connected quantum network with CNOT gates representing the interaction between the constituting qubits. We give a number of results for the equilibration in these systems, including analytic estimates. The results are checked using numerical methods for systems with up to 15-16 qubits. It is emphasized in which way the size of the network controls the convergency.

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Jaroslav Novotný, Angelo Mariano, Saverio Pascazio, Antonello Scardicchio, Igor Jex. 2020-09-28. Relaxation to Equilibrium in a Quantum Network. https://doi.org/10.1103/physreva.103.042218

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