A scalable architecture for quantum computation with molecular nanomagnets

TL;DR

This paper proposes a scalable quantum computing architecture using molecular nanomagnets coupled to superconducting resonators, demonstrating potential for universal quantum computation with realistic device parameters.

Contribution

It introduces a hybrid quantum processor design with a magnetic quantum electrodynamics model, enabling universal quantum operations on molecular spin qubits.

Findings

Hybrid devices can perform arbitrary single-qubit operations.

Tunable interactions allow for universal quantum gates.

Feasibility depends on developing molecules with long coherence times.

Abstract

A proposal for a magnetic quantum processor that consists of individual molecular spins coupled to superconducting coplanar resonators and transmission lines is carefully examined. We derive a simple magnetic quantum electrodynamics Hamiltonian to describe the underlying physics. It is shown that these hybrid devices can perform arbitrary operations on each spin qubit and induce tunable interactions between any pair of them. The combination of these two operations ensures that the processor can perform universal quantum computations. The feasibility of this proposal is critically discussed using the results of realistic calculations, based on parameters of existing devices and molecular qubits. These results show that the proposal is feasible, provided that molecules with sufficiently long coherence times can be developed and accurately integrated into specific areas of the device. This architecture has an enormous potential for scaling up quantum computation thanks to the microscopic nature of the individual constituents, the molecules, and the possibility of using their internal spin degrees of freedom.