QTC Seminar: "Quantum Sensing with Solid-State Atomic Qubits"
Thursday, March 14, 2019
2460 A.V. Williams Building
301 405 4471
Quantum Sensing with Solid-State Atomic Qubits
Speaker: Dr. Mark Ku, Harvard University
Quantum sensing with nitrogen vacancy (NV) center in diamond, a solid-state atomic qubit that can operate at room-temperature, is an emerging quantum technology which has potential for wide-ranging impact in the near future. In particular, an application that has begun to make a tangible impact is to probe advanced materials and devices in the nanoscale. In this talk, I discuss two works at Harvard where we apply NV centers to probe spintronic device and novel electronic transport in graphene. In the first work, we develop a technology with NV to probe magnetic spin-torque oscillator (STO), which is a candidate for on-chip, nanoscale microwave source. We demonstrate high spectral resolution with the technique, which opens the way for quantitative, nanoscale mapping of the STO microwave signal, a much-needed characterization capability for advanced STO research. In the second work, we directly observe the flow of a viscous electron fluid for the first time in graphene via imaging the associated stray magnetic field. The finding has implication for understanding and characterizing graphene devices, while the technique established here can be used to probe other novel electronic phenomena or circuits. To conclude, I present a future research vision of engineering and applying quantum sensing and information technologies based on NVs and other solid-state atomic qubits.
Mark Jen-Hao Ku is a postdoctoral researcher at Harvard University Department of Physics and Harvard-Smithsonian Center for Astrophysics. He attended the University of British Columbia, where he received B.Sc. in Mathematics and Physics and M.Sc. in Physics. He received Ph.D. in Physics at the Massachusetts Institute of Technology, where he used ultracold atomic gases for quantum simulation of high-temperature superfluid. He received a DARPA program best experimental paper award for the thermodynamic measurement of the superfluid published in Science. At Harvard, he uses nitrogen-vacancy centers in diamond as a quantum sensor to probe condensed matter phenomena, including spin-torque oscillator in ferromagnet and viscous electron fluid in graphene.