Tuneable on-demand single-photon source

TL;DR

This paper reports a tunable on-demand microwave photon source using a superconducting artificial atom, achieving over 75% efficiency and wide frequency tunability, crucial for quantum technologies.

Contribution

It introduces a controllable superconducting atom-based photon source with high efficiency and broad frequency tuning capabilities.

Findings

Efficiency exceeds 75%

Operates over 6.7 to 9.1 GHz range

Maintains high efficiency across tuning range

Abstract

An on-demand single photon source is a key element in a series of prospective quantum technologies and applications. We demonstrate the operation of a tuneable on-demand microwave photon source based on a fully controllable superconducting artificial atom strongly coupled to an open-end transmission line (a 1D half-space). The atom emits a photon upon excitation by a short microwave $\pi$-pulse applied through a control line weakly coupled to the atom. The emission and control lines are well decoupled from each other, preventing the direct leakage of radiation from the $\pi$-pulses used for excitation. The estimated efficiency of the source is higher than 75\% and remains to be about 50\% or higher over a wide frequency range from 6.7 to 9.1 GHz continuously tuned by an external magnetic field.