Exploring the use of quantum computers for resilience analysis in critical infrastructure networks

Abstract

Resilience analysis of networks representing critical infrastructure is a computationally hard problem, and the question arises of whether quantum computers may be beneficial for this purpose. On the way towards an answer to this problem, we map a small critical infrastructure network on a quantum network composed of dipole–dipole-coupled nodes. The latter are each equipped with up to three discrete (quantum) states, two of which support the connectivity of the network, while the third state, reachable through nondeterministic spontaneous processes, represents a ‘broken’ node. A finite ‘repair’ time is needed to restore the node. To study the dynamics of such networks on a quantum computer, we derive unitary dilations of Kraus operators governing the evolution of our open quantum network, and generate corresponding quantum circuits using the qiskit interface. We then study the population dynamics of several cases of increasing complexity on the quantum hardware. We discuss how scaling of errors is related to the depth of the quantum circuits. Ultimately, we show that open quantum systems can be used for modelling critical infrastructure, but quantum computers with much lower error rates than currently available are required for a quantitative resilience analysis.