Towards hybrid spin-mechanical systems in silicon carbide with helium ion implantation

Silicon carbide (SiC) is a suitable candidate for studying hybrid spin-mechanical systems due to its established use as a sensor material[1] and the capability of its hexagonal polytype (4H-SiC) to host highly coherent spin-centers[2], such as silicon vacancies (V_Si). To realize such a system, spin resonances associated with V_Si need to be coupled to the mechanical modes, which will allow more sensitive magnetic field sensing[3]. To achieve this, we will fabricate mechanical resonators in 4H-SiC and create V_Si by helium ion implantation.
To study the influence of created V_Si on the mechanical properties, we first considered a system with 3C-SiC (grown on Si) as shown in the figure, which provides higher-quality mechanical resonators compared to 4H-SiC grown on 4H-SiC. In our preliminary experiments, we implanted the resonators with broad beam He+ implantation to create ensembles of V_Si. We intend to show how the mechanical properties can be modified varying fluence, in terms of resonance frequencies, mechanical quality factors and, stress. In future, we plan to use focused He+ implantation to study the positional dependence and number of V_Si on the modification of the material. Finally, we will employ an Optically Detected Spin-Mechanical Resonance (ODSMR) scheme to characterize the coupling of spins and phonons[3].
References:
[1] F. Zhao et al., “Photoelectrochemical etching to fabricate single-crystal SiC MEMS for harsh environments”, Materials Letters 65, 409–412 (2011)
[2] D. Riedel et al., “Resonant Addressing and Manipulation of Silicon Vacancy Qubits in Silicon Carbide”, Phys.Rev.Lett.109, 226402 (2012)
[3] A. V. Poshakinskiy and G. V. Astakhov, "Optically detected spin-mechanical resonance in silicon carbide mem-branes”, PhysRevB.100.094104 (2019)