Optically Active Semiconductor Spin Qubits with Long Coherence Times Using Single Donor Impurities in ZnSe
Abstract
Scalable quantum technology requires solid-state qubits that possess long coherence times and also strongly interact with light. Single donor impurities in ZnSe can satisfy both requirements. They exhibit strong single photon emission through donor-bound exciton states with fast radiatively limited lifetimes. They also naturally possess a donor electron spin that can act as an optically active qubit in a potentially nuclear-spin free environment, enabling long coherence times. But many of the fundamental spin and optical properties of this material system are still poorly understood. Furthermore, the integration of these optically active qubits with nanophotonics, which is essential for efficient light-matter interfaces, has yet to be realized. In this program we will combine advanced materials growth with spectroscopy, atomic scale imaging, nanophotonic engineering, and theoretical modeling to develop optically active spin qubits using donor impurities in ZnSe and couple them to light. We will study the radiative properties of Cl and F donor impurities in these substrates using resonance fluorescence spectroscopy, enabling us to identify the fundamental radiative lifetime and emission linewidth, as well as the dominant line broadening mechanisms. We will use dark-state spectroscopy and coherent control to study the coherence properties of single donor spins both in conventional and isotopically purified materials that have virtually no nuclear spin. We will also study stacking faults as an alternate method to engineer confinement. Finally, we will couple these emitters to photonic crystal cavities togenerate strong light-matter interfaces, with the ultimate goal of achieving a coherent spin-photon interface. The experimental work will be complemented by atomistic models being developed by our collaborators. This program entails a strong collaborative effort between MBE growth, spectroscopy, materials characterization, and theoretical modeling. Success of this project will provide a new qubit system with bright, efficient, and coherent radiative emission combined with pristine spin properties in a material that supports wafer scale growth and planar nanofabrication. It would also strongly support the mission of the DoD to develop next generation scalable quantum technology suitable for quantum sensing, networking and computation.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 29, 2024
- Source ID
- FA95502310264
Entities
People
- Edo Waks
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Maryland