An integrated microwave-to-optics interface for scalable quantum computing

TL;DR

This paper introduces an integrated microwave-to-optics transducer with high efficiency, low noise, and broad bandwidth, advancing scalable quantum computing and networking capabilities.

Contribution

A novel integrated transducer design using superconducting resonators and lithium niobate achieves high efficiency, low noise, and scalability for quantum information transfer.

Findings

Transduction efficiency up to 0.9%

Added noise limited to a few photons

Bandwidth of 14.8 MHz and repetition rate of 100 kHz

Abstract

Microwave-to-optics transduction is emerging as a vital technology for scaling quantum computers and quantum networks. To establish useful entanglement links between qubit processing units, several key conditions have to be simultaneously met: the transducer must add less than a single quantum of input referred noise and operate with high-efficiency, as well as large bandwidth and high repetition rate. Here we present a new design for an integrated transducer based on a planar superconducting resonator coupled to a silicon photonic cavity through a mechanical oscillator made of lithium niobate on silicon. We experimentally demonstrate its unique performance and potential for simultaneously realizing all of the above conditions, measuring added noise that is limited to a few photons, transduction efficiencies as high as 0.9%, with a bandwidth of 14.8 MHz and a repetition rate of up to 100 kHz. Our device couples directly to a 50-Ohm transmission line and can easily be scaled to a large number of transducers on a single chip, paving the way for distributed quantum computing.