Probing Spin Dynamics on Diamond Surfaces Using a Single Quantum Sensor

Probing Spin Dynamics on Diamond Surfaces Using a Single Quantum Sensor

Dwyer, Bo L. (Harvard University)
Rodgers, Lila V.H. (Princeton University)
Urbach, Elana K. (Harvard University)
Bluvstein, Dolev (Harvard University)
Sangtawesin, Sorawis (Suranaree University of Technology, Nakhonratchasima)
Zhou, Hengyun (Harvard University)
Nassab, Yahia (Princeton University)
Fitzpatrick, Mattias (Princeton University)
Dobrovitski, V.V. (TU Delft QID/Dobrovitski Group; TU Delft QuTech Advanced Research Centre; Kavli institute of nanoscience Delft)

2022

Understanding the dynamics of a quantum bit's environment is essential for the realization of practical systems for quantum information processing and metrology. We use single nitrogen-vacancy (NV) centers in diamond to study the dynamics of a disordered spin ensemble at the diamond surface. Specifically, we reduce the density of "dark"surface spins to interrogate their contribution to the decoherence of shallow NV center spin qubits. When the average surface spin spacing exceeds the NV center depth, we find that the surface spin contribution to the NV center free induction decay can be described by a stretched exponential with variable power n. We show that these observations are consistent with a model in which the spatial positions of the surface spins are fixed for each measurement, but some of them reconfigure between measurements. In particular, we observe a depth-dependent critical time associated with a dynamical transition from Gaussian (n=2) decay to n=2/3, and show that this transition arises from the competition between the small decay contributions of many distant spins and strong coupling to a few proximal spins at the surface. These observations demonstrate the potential of a local sensor for understanding complex systems and elucidate pathways for improving and controlling spin qubits at the surface.

http://resolver.tudelft.nl/uuid:53553f0e-2e2e-492e-8a17-a4837053fa56

https://doi.org/10.1103/PRXQuantum.3.040328

PRX Quantum, 3 (4)

Institutional Repository

journal article

© 2022 Bo L. Dwyer, Lila V.H. Rodgers, Elana K. Urbach, Dolev Bluvstein, Sorawis Sangtawesin, Hengyun Zhou, Yahia Nassab, Mattias Fitzpatrick, V.V. Dobrovitski, More Authors