Physics

Dr. Waseem Akhtar
Laboratory Charles Coulomb, CNRS, Montpellier, France

Abstract:

Point Defects in semiconductor have been deleterious, however very often such point defects occurring due to vacancy or unsaturated bonds in the crystal is accompanied by an electron spin. Such spin centers are the simplest two level quantum systems that can be manipulated using magnetic resonance techniques and are excellent candidate for Quantum-bits as well as for nanoscale magnetometry. In this talk I will discuss my current research which is based on identifying single quantum emitters namely Nitrogen-Vacancy (NV) defect in Diamond and exploiting its spin dependent photoluminescence for nanoscale magnetic field sensing and imaging, a topic of crucial importance from material science to mesoscopic physics and life sciences. A single NV center attached at the apex of the scanning AFM tip in combination with home-built confocal microscopy provides an atomic size, non-invasive, quantitative and vectorial magnetic field sensor with nanoscale spatial resolution. I will show the tremendous capability of such a unique magnetometer for real space magnetic imaging of chiral magnetic textures such as skyrmions and spin cycloids in spintronic relevant magnetic thin films [1,2]. Our results highlights that the NV magnetometry is not only compatible with Ferromagnets but could also be employed for studying exotic spin structures in Antiferromagnets.

References : [1] I. Gross, W. Akhtar et al., Nature 549, 252 (2017). [2] I. Gross, W. Akhtar et al., Physical Review Materials, 2, 024406 (2018).