Sven Rogge

Affiliation: University of New South Wales

Research Interests: quantum electronics, quantum computation, silicon mesoscopic physics
Title: Erbium sites in silicon with long spin and optical coherence times
Abstract: In solid-state hosts at cryogenic temperatures, rare-earth ions such as Erbium offer low homogeneous broadening and long spin coherence, making them potential assets in optical quantum memories, optical-microwave transducers, and single photon emitters at telecommunication wavelengths. Our study leverages resonant photoluminescence excitation (PLE) spectroscopy to explore spin and optical properties of Er ensembles in silicon, using a setup that combines tailor-made superconducting single photon detectors and fibre optics for high collection efficiency and spectral measurements of samples with low Er density. We discovered that co-dopants like Oxygen, Boron, and Phosphorus have a substantial effect on optically active Er sites and their optical transition energies. Remarkably, we found the first telecom-compatible Er3+ sites in a nuclear-spin-free silicon crystal (<0.01%) with long optical and electron spin coherence times. Both investigated sites showed optical inhomogeneous linewidths around 100 MHz and homogeneous linewidths below 70 kHz. With electron spin coherence times measured via optically detected magnetic resonance and Hahn echo decay constants approximately 1ms at 12 mT, these Er3+ sites in silicon show promise for a multitude of quantum information processing applications.