Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 24: Poster Session: Ge/Si/SiC / III - V Semiconductors

HL 24.16: Poster

Montag, 26. März 2012, 16:00–19:00, Poster D

Light-induced electron spin resonance (LESR) studies of silicon vacancy centers in 6H-SiC — •Daniel Riedel¹, Andreas Sperlich¹, Hannes Kraus¹, Franziska Fuchs¹, Alexandra Soltamova², Pavel Baranov², Georgy Astakhov¹, and Vladimir Dyakonov^1,3 — ¹Experimental Physics VI, Julius Maximilian University of Würzburg, D-97074 Würzburg — ²Ioffe Physical-Technical Institute, St. Petersburg, RU-194021 Russia — ³ZAE Bayern, D-97074 Würzburg

The silicon vacancy V_Si centers in hexagonal polytypes of SiC, in particular 6H-SiC, have C_3v symmetry allowing for zero field splitting between spin sublevels in the ground state. Below-band-gap illumination of 6H-SiC samples results in nonequilibrium spin population, which is directly detected in our X-band (9.4 GHz) ESR setup. We investigated LESR as a function of temperature, illumination wavelength and intensity in order to find the most efficient conditions for initialization, manipulation and readout of the V_Si spin. The observed saturation of the LESR signal at relatively low illumination intensities and microwave powers indicates efficient optical spin pumping mechanism and long spin relaxation time, much longer than radiative lifetime in the excited states. Our observations suggest that V_Si centers are promising candidates for qubits.