Observation of the magneto-optic Voigt effect in a paramagnetic diamond membrane

Abstract

The magneto-optic Voigt effect is observed in a synthetic diamond membrane with a substitutional nitrogen defect concentration in the order of 200 ppm and a nitrogen-vacancy defect sub-ensemble generated through neutron irradiation and annealing. The measured polarisation rotation in the reflected light is observed to be quadratically proportional to the applied magnetic field and to the incident reflection angle. Additionally, it is observed to be modifiable by illuminating the diamond with a 532 nm laser. Spectral analysis of the reflected light under 532 nm illumination shows a slow narrowing of the spectral distribution, indicating a small increase in the overall magnetisation, as opposed to magnetisation degradation caused by heating. Further analysis of the optical power dependence suggest this may be related to a shift in the spin ensembles charge state equilibrium and, by extension, the resulting ensemble magnetisation.

Ultrafast opto-magnetic effects induced by nitrogen-vacancy centers in diamond crystals

“…To examine the possibility of the above hypothesis, we discuss the dynamics of the magnetization via NV centers in diamond. Figure 5 schematically shows the dynamics of the ICME (or inverse Voigt effect) [22] induced in a diamond single crystal.…”

“…For example, the magneto-optical Faraday effect was used to demonstrate nondestructive single-spin measurement in diamond. [21] Furthermore, the magneto-optical Voigt effect in a paramagnetic diamond membrane, with a high concentration of negatively charged NV − centers, has been recently demonstrated using a CW green laser, suggesting that a sub-ensemble of NV − centers plays a central role in the rotation of the incident linearly polarized light [22] provided that the electron spins associated with the NV − centers can be optically polarized into the 0 > ground state. [23] As a result, while there have been numerous studies on nonlinear OKE [14,24] and magnetooptical effects [21,22] in pure diamond and NV-diamond, the effects of NV centers on the inverse magneto-optical effect, that is the opto-magnetic effect, [25] have not yet been examined.…”

“…[21] Furthermore, the magneto-optical Voigt effect in a paramagnetic diamond membrane, with a high concentration of negatively charged NV − centers, has been recently demonstrated using a CW green laser, suggesting that a sub-ensemble of NV − centers plays a central role in the rotation of the incident linearly polarized light [22] provided that the electron spins associated with the NV − centers can be optically polarized into the 0 > ground state. [23] As a result, while there have been numerous studies on nonlinear OKE [14,24] and magnetooptical effects [21,22] in pure diamond and NV-diamond, the effects of NV centers on the inverse magneto-optical effect, that is the opto-magnetic effect, [25] have not yet been examined. An understanding of this opto-magnetic effect is, however, critical for the pursuit of further research into novel functionality of diamond nonlinear photonics so as to advance quantum sensing technology using magnetic fields or spin.…”