Implementing universal quantum gates in coupled cavities

TL;DR

This paper demonstrates how to implement universal quantum gates in a coupled cavity array system, enabling scalable quantum computation with polaritons as qubits, and discusses potential experimental realizations.

Contribution

It introduces a method to construct and manipulate qubits from polaritons in coupled cavities, deriving the system dynamics and showing how to achieve universal quantum gates.

Findings

System dynamics follow an XY Hamiltonian

Non-local quantum gates can be implemented

Universal quantum computation is feasible in this system

Abstract

We study a linear array of coupled cavities interacting with two level systems and show how to construct individually addressable qubits in this system from the long-lived atom-photon excitations (polaritons) at each site. We derive the system dynamics and show that is described by an XY Hamiltonian. We proceed by showing how to implement non-local quantum gates and show that combined with the inherent ability for individual addressing, universal quantum computation is possible in this system. We finally discuss the prospects for experimental implementation using various technologies involving dopants as atoms, quantum dots or Cooper pair boxes.