Room-temperature photonic quantum computing in integrated silicon photonics with germanium-silicon single-photon avalanche diodes

TL;DR

This paper proposes room-temperature integrated GeSi single-photon avalanche diodes for photonic quantum computing, demonstrating their competitive performance against traditional superconducting detectors and enabling scalable, high-performance quantum systems.

Contribution

It introduces GeSi SPADs operable at room temperature for PQC, with photon-number-resolving capabilities using multiplexed arrays, advancing practical scalable quantum photonic technologies.

Findings

GeSi SPADs operate effectively at 300 K.

Performance metrics are competitive with SNSPDs.

High-performance room-temperature quantum computing architecture is predicted.

Abstract

Most, if not all, photonic quantum computing (PQC) relies upon superconducting nanowire single-photon detectors (SNSPDs) based on niobium (Nb) operated at a temperature < 4 K. This paper proposes and analyzes 300 K waveguide-integrated germanium-silicon (GeSi) single-photon avalanche diodes (SPADs) based on the recently demonstrated normal-incidence GeSi SPADs operated at room temperature, and shows that their performance is competitive against that of SNSPDs in a series of metrics for PQC with a reasonable time-gating window to resolve the issue of dark-count rate (DCR). These GeSi SPADs become photon-number-resolving avalanche diodes (PNRADs) by deploying a spatially-multiplexed M-fold-waveguide array of M GeSi SPADs. Using on-chip waveguided spontaneous four-wave mixing (SFWM) sources and waveguided field-programmable interferometer mesh (FPIM) circuits, together with the high-metric SPADs and PNRADs, high-performance quantum computing at room temperature is predicted for this PQC architecture.