Title: Quantum Sensing at the Atomically Thin Limit

Abstract: Solid-state spin defects have revolutionized quantum sensing by enabling nanoscale
measurements with subwavelength spatial resolution and sensitivity to diverse physical signals.
To fully harness these capabilities, one must minimize both the distance between the sensor and
the target, as well as the smallest detectable signal. However, established systems such as
nitrogen-vacancy centers in diamond often face limitations when operated close to surfaces or
confined to nanoscale volumes, motivating the exploration of spin-active defects in novel,
atomically thin materials. 

In this talk, I will present an experimental framework for studying a new two-dimensional spin
ensemble hosted in hexagonal boron nitride (hBN). I will discuss how we probe the spin
Hamiltonian, characterize coherent sensing dynamics, and identify the noise environment of this
2D platform. By precisely mapping hyperfine interactions with nearby nuclear spins, we
demonstrate controllable switching between magnetic and electric field sensing, as well as
develop strategies to build atomic registers. I will also introduce a new method for reconstructing
the local noise spectrum that directly accounts for imperfections in quantum control.

Our measurements reveal a coherence time of up to 0.1 milliseconds and AC magnetic
sensitivities at the nanotesla level for targets only 10 nanometers away – approaching the regime
needed to detect single nuclear spins. These advances, together with the design flexibility of
atomically thin hosts like hBN, open pathways toward next-generation quantum sensors that
combine ultrahigh sensitivity, tunable noise selectivity, and reconfigurable quantum
functionalities.

Bio: Souvik Biswas is an incoming Assistant Professor at the University of Michigan, Electrical
Engineering and Computer Science, starting Fall 2026. He is currently a postdoctoral research
affiliate at Stanford University in Electrical Engineering. His research focuses on developing
high-fidelity, scalable quantum systems by leveraging solid-state spin-photon interfaces,
including low-dimensional materials, diamond, and silicon carbide. He received his Ph.D. in
Applied Physics from the California Institute of Technology, where he focused on spectroscopic
studies of engineered excitons in two-dimensional materials and the development of atomically
thin reconfigurable nanophotonics. His work has been recognized by 2024 LSA Rising Stars of
Light, 2024 Rising Stars in MSE, and 2022 MRS Graduate Student Gold Award.