Solid-State Quantum Memories for Near-Term Quantum Repeaters

Abstract

Over the past decade, quantum computers have emerged as a promising technology to enable transformational advances in information processing and communication and solve problems that are intractable to classical computers. While there is great promise in linking quantum computers together over long distances via quantum channels, these technologies are still under development. Solid-state emitters with coherent spin-photon interfaces, long spin lifetimes, and narrow optical transitions are a leading platform for use as quantum memories in networked quantum repeaters. However, while such emitters have already enabled advanced quantum networking demonstrations in laboratory settings, applying these devices as useful memory devices at scale is a key outstanding challenge. In this thesis, we experimentally investigate solid-state quantum memories for quantum information applications. First, we develop experimental techniques to characterize solid-state emitters with high throughput, enabling both better understanding of the distribution of emitter properties and improved feedback on material preparation and device fabrication. Next, we implement quantum frequency conversion to create a coherent spin-photon interface between silicon-vacancy centers in diamond and optical photons in the low-loss telecom band. Finally, we investigate color centers in other engineering materials, including silicon and silicon carbide, to better understand the fundamental trade space of requirements for solid-state hosts. Together, these efforts represent a significant advance in creating, controlling, and deploying telecom-compatible spin interfaces, paving the way for memory-enabled quantum repeaters.