Long optical and electron spin coherence times for erbium ions in silicon

Abstract

Spins in silicon that are accessible via a telecom-compatible optical transition are a versatile platform for quantum information processing that can leverage the well-established silicon nanofabrication industry. Key to these applications are long coherence times on the optical and spin transitions to provide a robust system for interfacing photonic and spin qubits. Here, we report telecom-compatible Er3+ sites with long optical and electron spin coherence times, measured within a nuclear spin-free silicon crystal (<0.01 % 29Si) using optical detection. We investigate two sites and find 0.1 GHz optical inhomogeneous linewidths and homogeneous linewidths below 70 kHz for both sites. We measu..