Joonhee Choi - Stanford University

Tuesday 28 Oct 2025, 12:00 → 21:00 US/Eastern

IAMM

Wonhee Ko (University of Tennessee, Knoxville)

https://choilab.stanford.edu/

13:00 → 13:20 Pick up at Conference

Travel to IAMM.

Speaker: Wonhee Ko (University of Tennessee, Knoxville)

13:20 → 14:20 Quantum sensing with a spin ensemble in a two-dimensional material

Quantum sensing with solid-state spin defects has transformed nanoscale metrology, offering sub-wavelength spatial resolution with exceptional sensitivity to multiple signal types. Maximizing these advantages requires minimizing both the sensor-target separation and detectable signal threshold. However, leading platforms such as nitrogen-vacancy centers in diamond suffer performance degradation near surfaces or in nanoscale volumes, motivating the search for optically addressable spin sensors in atomically thin, 2D materials. Here, we present an experimental framework to probe a novel 2D spin ensemble, including its Hamiltonian, coherent sensing dynamics, and noise environment. We achieve a record coherence time of 80 μs and nanotesla-level AC magnetic sensitivity at a 10 nm target distance, reaching the threshold for detecting a single nuclear spin in nanoscale spectroscopy. Leveraging the broad opportunities for defect engineering in atomically thin hosts, these results lay the foundation for next-generation quantum sensors with ultrahigh sensitivity, tunable noise selectivity, and versatile quantum functionalities.

14:20 → 14:30 Break

14:30 → 15:00 Research Meeting

Speaker: Yang Zhang

15:00 → 15:30 Research Meeting

Speaker: Joon Sue Lee (University of Tennessee, Knoxville)

15:30 → 16:00 Research Meeting

Speaker: Ruixing Zhang (Department of Physics and Astronomy, University of Tennessee Knoxville)

16:00 → 16:30 Research Meeting

16:30 → 17:00 Research Meeting

Speaker: Wonhee Ko (University of Tennessee, Knoxville)