Photons, Magnons and Quantum Technologies – NV centers in SiC

Team

• Permanent members: Benoît Eble, Sophie Hameau, Florent Margaillan

When defects are present in a crystalline solid, they break the translational symmetry of the lattice and new electronic and optical properties appear. The point defect called “colored NV center” is one of the most studied defects for its promising applications in high precision magnetometry or in the field of quantum computing. Indeed, the NV center can be considered as a quantum bit (elementary brick of quantum computing) because it is a quantum system well protected from the environment and has an electron spin S = 1 which can be optically manipulated. The complete study of the NV center has already been carried out in diamond but there are still two obstacles to its technological use. On the one hand, diamond is hard to produce and therefore expensive. On the other hand, the optical response of the NV center of diamond is at 637nm, in the visible range of electromagnetic waves, and thus is not optimal for transmission via optical fiber for example. Silicon carbide brings a solution to these two problems, since the knowledge and the manufacturing methods concerning it are very mature because of the massive use of silicon in microelectronics since decades. Finally, the optical response of the NV center in SiC is in the near infrared wavelength range much more efficient for distant exchange of information.

In SiC the NCVSi center is a complex formed by a nitrogen atom in substitution of a carbon and a silicon vacancy in the crystal. We have identified, through a joint study with the CONFID team of INSP, the NV center in the 4H hexagonal polytype. We are currently conducting a study of the formation of this defect in the cubic polytype. 

In parallel, we are setting up an ODMR (optical magnetic resonance detection) experiment. ODMR is a fine spectrometry technique, which allows to detect optically the spin reversal of the NV center.

Collaborations

• J.-L. Cantin, J. von Bardeleben, INSP

Publications

• S. Zargaleh, Sophie Hameau, Benoit Eble, F. Margaillan, Hans Jürgen von Bardeleben, et al.. Nitrogen vacancy center in cubic silicon carbide: A promising qubit in the 1.5μm spectral range for photonic quantum networks. Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society, 2018. ⟨hal-01902627⟩
• S. Zargaleh, H. von Bardeleben, J. Cantin, U. Gerstmann, S. Hameau, et al.. Electron paramagnetic resonance tagged High Resolution Excitation Spectroscopy of NV-Centers in 4H-SiC. Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society, 2018, 98 (21), pp.214113. ⟨10.1103/PhysRevB.98.214113⟩. ⟨hal-02298324⟩