Abstract: Optically-active spins in the solid-state are useful resources for quantum technologies. The coupling of such systems to photonic structures can generate deterministic spin-photon entanglement, which could contribute to quantum simulations and networking. Ideal spin systems for such applications must combine high quality spin and photonic properties, as well as efficient methods for the coherent manipulation of the spin state. While common methods for controlling the quantum state of spin qubits utilize microwave fields, such methods become challenging in many optically-active spin systems that exhibit low g-factors. In this talk, I will introduce an alternative method, based on a two-photon Raman excitation, for coherently manipulating spins in systems for which microwave control is challenging. I will present our all-optical approach for performing noise spectroscopy of solid-state spins, which leverages such Raman-based control to implement pulse sequences inspired by nuclear magnetic resonance. Such realization of noise spectroscopy allowed us to directly probe the high frequency (up to 100 MHz) noise spectra of single electrons confined in an InAs/GaAs quantum dots, in agreement with theoretical models that consider the hyperfine interaction of such electrons with an ensemble of nuclear spins broadened by strain. After discussing the noise spectra of InAs/GaAs quantum dots, I will introduce additional systems with promising spin and optical properties that we plan to study using similar noise spectroscopy approaches. Finally, I will present our research directions on the coupling of spins to fabricated photonic structures. Combining such coupling with all-optical coherent control could enable the realization of novel pulse sequences for high resolution sensing, quantum information processing and quantum networking.
Joint Quantum Institute Seminars take place live each Monday during Fall and Spring Semesters, 11:00 a.m. - 12:00 p.m. Eastern Time, in Room 2400 of the Atlantic Building. University of Maryland affiliates may participate using Zoom. The Seminars are also simulcast world-wide on the Joint Quantum Institute YouTube channel, https://www.youtube.com/user/JQInews(link is external), which supports audience participation in the chat interface.