A "Single-Photon" Transistor in Circuit Quantum Electrodynamics

TL;DR

This paper proposes a scalable circuit quantum electrodynamics setup for a single-photon transistor, where a single photon can control photon propagation in another line without exchanging photons, enabling high on-off ratios.

Contribution

It introduces a novel, scalable single-photon transistor design using coupled transmon qubits in circuit QED with potential for integrated quantum photonic circuits.

Findings

High on-off ratios achievable with feasible parameters

No photon exchange between transmission lines during operation

Scalable design with identical pulse shapes and frequencies

Abstract

We introduce a circuit quantum electrodynamical setup for a "single-photon" transistor. In our approach photons propagate in two open transmission lines that are coupled via two interacting transmon qubits. The interaction is such that no photons are exchanged between the two transmission lines but a single photon in one line can completely block respectively enable the propagation of photons in the other line. High on-off ratios can be achieved for feasible experimental parameters. Our approach is inherently scalable as all photon pulses can have the same pulse shape and carrier frequency such that output signals of one transistor can be input signals for a consecutive transistor.