High-Fidelity Ion State Detection Using Trap-Integrated Avalanche Photodiodes

TL;DR

This paper demonstrates high-fidelity, room-temperature ion state detection using integrated single-photon avalanche diodes on silicon chips, enabling faster, more portable quantum information processing with potential for parallel operations.

Contribution

It introduces the integration of SPADs directly into silicon ion trapping chips for the first time, achieving near-perfect fidelity in ion state detection at room temperature.

Findings

Achieved 99.92% average fidelity in ion state detection

Demonstrated detection within 450 microseconds

Enabled potential for scalable, integrated quantum devices

Abstract

Integrated technologies greatly enhance the prospects for practical quantum information processing and sensing devices based on trapped ions. High-speed and high-fidelity ion state readout is critical for any such application. Integrated detectors offer significant advantages for system portability and can also greatly facilitate parallel operations if a separate detector can be incorporated at each ion-trapping location. Here we demonstrate ion quantum state detection at room temperature utilizing single-photon avalanche diodes (SPADs) integrated directly into the substrate of silicon ion trapping chips. We detect the state of a trapped $^{88}\text{Sr}^{+}$ ion via fluorescence collection with the SPAD, achieving $99.92(1)\%$ average fidelity in 450 $\mu$s, opening the door to the application of integrated state detection to quantum computing and sensing utilizing arrays of trapped ions.