Detection of paramagnetic spins with an ultrathin van der Waals quantum sensor

Bibliographic Details
Title: Detection of paramagnetic spins with an ultrathin van der Waals quantum sensor
Authors: Robertson, Islay O., Scholten, Sam C., Singh, Priya, Healey, Alexander J., Meneses, Fernando, Reineck, Philipp, Abe, Hiroshi, Ohshima, Takeshi, Kianinia, Mehran, Aharonovich, Igor, Tetienne, Jean-Philippe
Source: ACS Nano, 17, 14, 13408-13417 (2023)
Publication Year: 2023
Collection: Condensed Matter
Subject Terms: Condensed Matter - Mesoscale and Nanoscale Physics
More Details: Detecting magnetic noise from small quantities of paramagnetic spins is a powerful capability for chemical, biochemical, and medical analysis. Quantum sensors based on optically addressable spin defects in bulk semiconductors are typically employed for such purposes, but the 3D crystal structure of the sensor inhibits the sensitivity by limiting the proximity of the defects to the target spins. Here we demonstrate the detection of paramagnetic spins using spin defects hosted in hexagonal boron nitride (hBN), a van der Waals material which can be exfoliated into the 2D regime. We first create negatively charged boron vacancy (V$_{\rm B}^-$) defects in a powder of ultrathin hBN nanoflakes ($<10$~atomic monolayers thick on average) and measure the longitudinal spin relaxation time ($T_1$) of this system. We then decorate the dry hBN nanopowder with paramagnetic Gd$^{3+}$ ions and observe a clear $T_1$ quenching, under ambient conditions, consistent with the added magnetic noise. Finally, we demonstrate the possibility of performing spin measurements including $T_1$ relaxometry using solution-suspended hBN nanopowder. Our results highlight the potential and versatility of the hBN quantum sensor for a range of sensing applications, and pave the way towards the realisation of a truly 2D, ultrasensitive quantum sensor.
Comment: 19 pages, 11 figures
Document Type: Working Paper
DOI: 10.1021/acsnano.3c01678
Access URL: http://arxiv.org/abs/2302.10560
Accession Number: edsarx.2302.10560
Database: arXiv
More Details
DOI:10.1021/acsnano.3c01678