Event Details

Condensed Matter webinar

Nanoscale quantum probes based on optically active spins in diamond are a versatile platform for studying solid state and living systems in a non-invasive way. They can be embedded in a sample of interest and can thus provide in situ, nanoscale information for few-molecule NMR and for imaging electronic spin textures in exotic materials [1,2].

In this talk, I will present results on quantum sensing using Nitrogen-Vacancy centres (NVs) in diamond nanostructures. Here, a quantum sensor composed of a dense, interacting spin ensemble in a diamond nanobeam can operate as a collection of independent sensors[3]. We experimentally demonstrate fault-¬tolerant decoupling of spin¬-spin interactions, achieving a five-¬fold enhancement of the spin coherence time. This is made possible by a novel dynamical decoupling sequence that simultaneously suppresses disorder, interactions, and imperfections in control operations[4]. We utilize the extended coherence time to demonstrate an increase in magnetic field sensitivity of over 40% compared to conventional sensing protocols such as the XY¬8 sequence. These results demonstrate a significant enhancement by breaking the natural interaction limit of dense ensembles, and reveal the potential of tailored control in complex, interacting ensembles.

[1] Holzgrafe et al., Phys. Rev. Appl. 13, 044004 (2020)

[2] Stefan et al., arXiv:2101.10331 (2021)

[3] Zhou et al., Phys. Rev. X 10 031003 (2020)

[4] Choi et al., Phys. Rev. X 10 031002 (2020)

If you have not received a Teams link for this event and would like to attend, please contact Dr. Michael Thompson.