Quantum computing with and for many-body physics

TL;DR

This review explores how quantum computing leverages many-body physics, detailing the use of quantum processors for simulating complex fermionic systems and discussing methods, entanglement, and decoherence in quantum devices.

Contribution

It provides a comprehensive overview of the integration of many-body physics with quantum computing, including hardware, mapping techniques, and simulation methods.

Findings

Quantum processors can simulate large fermionic systems.

Mapping fermionic Hamiltonians onto qubits enables practical simulations.

Entanglement and decoherence are critical factors in quantum many-body computations.

Abstract

Quantum computing technologies are making steady progress. This has opened new opportunities for tackling problems whose complexity prevents their description on classical computers. A prototypical example of these complex problems are interacting quantum many-body systems: on the one hand, these systems are known to become rapidly prohibitive to describe using classical computers when their size increases. On the other hand, these systems are precisely those which are used in the laboratory to build quantum computing platforms. This arguably makes them one of the most promising early use cases of quantum computing. In this review, we explain how quantum many-body systems are used to build quantum processors, and how, in turn, current and future quantum processors can be used to describe large many-body systems of fermions such as electrons and nucleons. The review includes an introduction to analog and digital quantum devices, the mapping of Fermi systems and their Hamiltonians onto qubit registers, as well as an overview of methods to access their static and dynamical properties. We also highlight some aspects related to entanglement, and touch on the description, influence and processing of decoherence in quantum devices.