EPJ Quantum Technol. (2015) 2: 22
https://doi.org/10.1140/epjqt/s40507-015-0035-z

Research

Longitudinal spin relaxation in nitrogen-vacancy ensembles in diamond

¹ Institute of Physics, Jagiellonian University, Łojasiewicza 11, Kraków, 30-348, Poland
² Department of Physics, University of California, Berkeley, CA, 94720-7300, USA
³ Helmholtz Institute, Johannes-Gutenberg University, Mainz, Germany

^* e-mail: mariusz.mrozek@doctoral.uj.edu.pl
^** e-mail: gawlik@uj.edu.pl

Received: 14 May 2015
Accepted: 13 October 2015
Published online: 29 October 2015

Abstract

We present an experimental study of the longitudinal electron-spin relaxation of ensembles of negatively charged nitrogen-vacancy (NV⁻) centers in diamond. The measurements were performed with samples having different NV⁻ concentrations and at different temperatures and magnetic fields. We found that the relaxation rate increases when transition frequencies in NV⁻ centers with different orientations become degenerate and interpret this as cross-relaxation caused by dipole-dipole interaction.