Magnetic circular dichroism and site-selective optically detected magnetic resonance of the deep amphoteric vanadium impurity in 6H-SiC

Abstract

Magnetic-circular-dichroism (MCD) absorption and optically detected electron-spin-resonance (ESR) data for the neutral vanadium impurity, Vhigh4plus(3dhigh1) on the alpha, beta and gamma sites in 6H-SiC are presented and supplemented by linearly polarized absorption and luminescence spectra. An analysis of the linearly polarized spectra yields crystal-field-level schemes in zero magnetic field and an intensity parameter u for Vhigh4plus on each of the three Si sites. This information is used to account for the Vhigh4plus MCD zero-phonon-line positions, signs, and relative intensities without an adjustable parameter. Evidence of Jahn-Teller effects is found in both the Vhigh4plus high2 E ground and the high2 T sub2 excited states. The MCD-ESR technique, in the present case, is site selective. The Vhigh4plus resonances associated with the beta and gamma site are virtually identical and cannot be distinguished by conventional ESR. The g factors for all three sites are satisfactorily expla ined within the framework of crystal-field theory

Optical Properties of Vanadium in 4 H Silicon Carbide for Quantum Technology

“…The width of the α lines at temperatures below 30 K is below the spectrometer resolution (∼ 35 GHz), while the β feature is of approximately that width. Previous measurements in 6H-SiC however indicate that an unresolved doublet may give rise to the observed β linewidth [21]. At low temperature, the α doublet makes up over 50 % of the recorded luminescence.…”

Vanadium spin qubits as telecom quantum emitters in silicon carbide

“…For generality, we use the unassigned site names of  and  in 4H-SiC and , , and  in 6H-SiC; the question of site assignment will be further discussed along the experimental results. Similarly, the ground and excited states separated by the crystal field are labeled GS1 and GS2 and ES1, ES2, and ES3 for generality and are related to the  4 and  5,6 irreducible representations (17). We first characterize the V 4+ orbital structure using resonant excitation of the ensemble optical transitions (Fig.…”

Electronic structure and magnetic properties of transition-metal-doped3Cand4Hsilicon carbide

“…Early transition metals ͑TMs͒, such as titanium, vanadium, and chromium, are common impurities in crystalline SiC grown by the Lely technique and have been thoroughly studied by various experimental methods. [1][2][3][4][5][6][7][8] While impurity related traps are often undesirable, they can also be introduced intentionally to create semi-insulating material. The study of the electronic structures of such defects is important for understanding the nature of the defect levels and so for the design of SiC devices.…”