Quantum interface between photonic and superconducting qubits

TL;DR

This paper proposes a fast, efficient quantum interface between photonic and superconducting qubits using optically active quantum dots in microwave cavities, enabling near-unity conversion efficiency and deterministic quantum state transfer.

Contribution

It introduces a novel scheme utilizing quantum dots in microwave cavities for high-speed quantum transduction and state transfer between photonic and superconducting qubits.

Findings

Bi-directional microwave-optics conversion feasible in nanoseconds

Conversion efficiencies approaching unity possible with current technology

Protocol for deterministic quantum state transfer from photonic to transmon qubits

Abstract

We show that optically active coupled quantum dots embedded in a superconducting microwave cavity can be used to realize a fast quantum interface between photonic and transmon qubits. Single photon absorption by a coupled quantum dot results in generation of a large electric dipole, which in turn ensures efficient coupling to the microwave cavity. Using cavity parameters achieved in prior experiments, we estimate that bi-directional microwave-optics conversion in nanosecond timescales with efficiencies approaching unity is experimentally feasible with current technology. We also outline a protocol for in-principle deterministic quantum state transfer from a time-bin photonic qubit to a transmon qubit. Recent advances in quantum dot based quantum photonics technologies indicate that the scheme we propose could play a central role in connecting quantum nodes incorporating cavity-coupled superconducting qubits.