Abstract: Quantum sensing with solid-state spins presents a promising avenue for achieving highly sensitive measurements of magnetic and electric fields, temperature, and pressure, as well as for probing quantum-mechanical many-body interactions with neighboring particles at the nanoscale. This approach leverages the unique properties of atomic-scale defects, such as nitrogen- or tin-vacancy centers in diamonds, rare-earth ions in crystals, and optically addressable spins in two-dimensional materials, to surpass classical sensing limits. By employing error-robust control techniques tailored to specific sensing signals and sensor characteristics, solid-state quantum sensors can achieve ultrahigh sensitivity and superior spatial resolution. In this talk, I will introduce several examples of recent advancements in nanoscale quantum sensors and their applications, including the engineering of high-density rare-earth ion ensembles for probing many-body interactions—leading to the preparation of time-crystalline states—and the exploration of spin qubits for precision quantum sensing in two-dimensional van der Waals materials.

Bio: Joonhee Choi is an Assistant Professor of Electrical Engineering at Stanford University. Joonhee received his Ph.D. and master’s from Harvard University, as well as master’s and bachelor’s degrees from Korea Advanced Institute of Science & Technology. Prior to joining Stanford, he worked as an IQIM postdoctoral fellow at the Institute for Quantum Information and Matter (IQIM) at Caltech. His research spans a diverse range of fields, including nonlinear nano-optics, ultrafast phenomena, solid-state and atomic physics, and quantum many-body physics. Currently, Joonhee focuses on practical applications in quantum metrology, communication, and information processing. Joonhee is the recipient of the Outstanding Young Researcher Award from the Association of Korean Physicists in America, the winner of the 2024 KSEA Young Investigator Grant in Science and has been appointed as a Terman Faculty Fellow in the School of Engineering at Stanford.

This seminar is sponsored by the Department of Applied Physics and the Ginzton Laboratory