How to Identify, Attribute, and Quantify Triplet Defects in Ensembles of Small Nanoparticles

Takuya F Segawa; Alexander I Shames

doi:10.1021/acs.jpclett.0c01922

How to Identify, Attribute, and Quantify Triplet Defects in Ensembles of Small Nanoparticles

J Phys Chem Lett. 2020 Sep 3;11(17):7438-7442. doi: 10.1021/acs.jpclett.0c01922.

Authors

Takuya F Segawa¹, Alexander I Shames²

Affiliations

¹ Laboratory for Solid State Physics, Eidgenössische Technische Hochschule (ETH) Zürich, CH-8093 Zürich, Switzerland.
² Department of Physics, Ben-Gurion University of the Negev, 8410501 Beer-Sheva, Israel.

PMID: 32787299
DOI: 10.1021/acs.jpclett.0c01922

Abstract

Nanodiamonds containing negatively charged triplet (having an electron spin S = 1) nitrogen-vacancy (NV^-) centers are an extraordinary room-temperature quantum system, whose electron spins may be polarized and read out optically even in a single nanocrystal. In this Viewpoint we promote a simple but reliable method to identify, attribute, and quantify these triplet defects in a polycrystalline sample using electron paramagnetic resonance (EPR) spectroscopy. The characterization relies on a specific "forbidden" transition ("ΔM_S = 2"), which appears at about half the central magnetic field and shows a remarkably small anisotropy. In particular, we emphasize that this method is by far not limited to NV^- centers in diamond but could become an important characterization tool for novel triplet defects in various types of nanoparticles.