Heterogeneous integration of spin-photon interfaces with a scalable CMOS platform

TL;DR

This paper introduces a scalable quantum hardware architecture called QSoC that integrates spin qubits in diamond with CMOS technology, enabling large-scale quantum computing with improved fabrication, calibration, and scalability.

Contribution

The work presents a novel modular quantum system-on-chip architecture integrating spin qubits with CMOS, addressing scaling challenges in quantum hardware.

Findings

Demonstrated fabrication of QSoC via lock-and-release method

Achieved high-throughput calibration for spin qubit registration

Enabled spectral tuning and efficient spin-state measurement

Abstract

Color centers in diamonds have emerged as a leading solid-state platform for advancing quantum technologies, satisfying the DiVincenzo criteria and recently achieving a quantum advantage in secret key distribution. Recent theoretical works estimate that general-purpose quantum computing using local quantum communication networks will require millions of physical qubits to encode thousands of logical qubits, which presents a substantial challenge to the hardware architecture at this scale. To address the unanswered scaling problem, in this work, we first introduce a scalable hardware modular architecture "Quantum System-on-Chip" (QSoC) that features compact two-dimensional arrays "quantum microchiplets" (QMCs) containing tin-vacancy (SnV-) spin qubits integrated on a cryogenic application-specific integrated circuit (ASIC). We demonstrate crucial architectural subcomponents, including (1) QSoC fabrication via a lock-and-release method for large-scale heterogeneous integration; (2) a high-throughput calibration of the QSoC for spin qubit spectral inhomogenous registration; (3) spin qubit spectral tuning functionality for inhomogenous compensation; (4) efficient spin-state preparation and measurement for improved spin and optical properties. QSoC architecture supports full connectivity for quantum memory arrays in a set of different resonant frequencies and offers the possibility for further scaling the number of solid-state physical qubits via larger and denser QMC arrays and optical frequency multiplexing networking.