MIT.nano's video: Guoqing Wang Develop better quantum sensors and simulators with solid state spins

Guoqing Wang, PhD Candidate in Nuclear Science and Engineering at MIT, delivered the Nano Explorations talk on November 8, 2022. Quantum sensors, such as spin defects in diamond, have achieved excellent performance by combining high sensitivity with spatial resolution. Unfortunately, these sensors can only detect signal fields with frequency in a few accessible ranges (a narrow window around the sensors’ resonance frequency), and extracting vectorial information usually satisfies the sensor's nanoscale spatial resolution. In this talk, Wang introduces recent work on sensing arbitrary-frequency vector signals by using the sensor qubit as a quantum frequency mixer. The technique leverages nonlinear effects in periodically driven (Floquet) quantum systems to achieve quantum frequency mixing of the signal and an applied bias AC field. The frequency-mixed field can be detected using well-developed sensing techniques such as Rabi and CPMG. In addition to enhancing the sensing performance by mediating spin transitions, the synthetic Floquet energy levels can improve the capabilities of quantum simulators, which is reported in another of Wang and his colleagues' work. By implementing modulated driving and performing projective measurements (generalized Rabi oscillation), they can engineer and characterize dynamical symmetries in time domain. In summary, Wang discusses how their contributions are paving the way for building more powerful quantum sensors and simulating more interesting phases. ------------------------------------------------------ Nano Explorations is a virtual seminar series powered by MIT.nano that features presentations by MIT students and postdocs on their work in nanoscience, nanotechnology, and other advanced research fields. The series was launched as a way to keep our nano community connected during the COVID-19 pandemic. Presentations take place once a month and are open to any interested viewers. Read more about past and upcoming Nano Explorations at mitnano.mit.edu/nano-explorations.