Scalable and High-Fidelity Quantum Random Access Memory in Spin-Photon Networks

TL;DR

This paper proposes scalable, high-fidelity quantum random access memory architectures using photonic integrated circuits and solid-state memories, leveraging existing components and error detection for quantum networks.

Contribution

It introduces two novel qRAM schemes based on photonic circuits and quantum teleportation, extending their application to quantum networks with built-in error detection.

Findings

Theoretical analysis shows high efficiency and fidelity of the proposed qRAM designs.

Both implementations utilize demonstrated components like electro-optic modulators and nanocavities.

Proposals are viable for near-term quantum computing and networking applications.

Abstract

A quantum random access memory (qRAM) is considered an essential computing unit to enable polynomial speedups in quantum information processing. Proposed implementations include using neutral atoms and superconducting circuits to construct a binary tree, but these systems still require demonstrations of the elementary components. Here, we propose a photonic integrated circuit (PIC) architecture integrated with solid-state memories as a viable platform for constructing a qRAM. We also present an alternative scheme based on quantum teleportation and extend it to the context of quantum networks. Both implementations rely on already demonstrated components: electro-optic modulators, a Mach-Zehnder interferometer (MZI) network, and nanocavities coupled to artificial atoms for spin-based memory writing and retrieval. Our approaches furthermore benefit from built-in error-detection based on photon heralding. Detailed theoretical analysis of the qRAM efficiency and query fidelity shows that our proposal presents viable near-term designs for a general qRAM.