Topology identification of autonomous quantum dynamical networks

TL;DR

This paper develops analytical conditions and an implementable algorithm for reconstructing the interaction topology of autonomous quantum networks from measurement data, with applications in quantum communication, computing, and sensing.

Contribution

It provides the first analytical solvability conditions and a practical reconstruction algorithm for quantum network topology identification.

Findings

Analytical solvability conditions derived for quantum network topology identification.

An efficient algorithm implemented and tested on quantum walk models.

Successful numerical reconstruction of Hamiltonians demonstrating the method's effectiveness.

Abstract

Topology identification comprises reconstructing the interaction Hamiltonian of a quantum network by properly processing measurements of its density operator within a fixed time interval. It finds application in several quantum technology contexts, ranging from quantum communication to quantum computing or sensing. In this paper, we provide analytical conditions for the solvability of the topology identification problem for autonomous quantum dynamical networks. The solvability condition is then converted in an algorithm for quantum network reconstruction that is easily implementable on standard computer facilities. The obtained algorithm is tested for Hamiltonian reconstruction on numerical examples based on the quantum walks formalism.