Ligand hyperfine interactions at silicon vacancies in 4H-SiC
Autor: | Takeshi Ohshima, Ivan Gueorguiev Ivanov, Nguyen Tien Son, Pontus Stenberg, Jawad ul Hassan, Valdas Jokubavicius |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
Physics
Silicon chemistry.chemical_element 02 engineering and technology Electronic structure 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Spectral line law.invention Paramagnetism chemistry law Vacancy defect Lattice (order) 0103 physical sciences silicon vacancy hyperfine interaction electron paramagnetic resonance General Materials Science Atomic physics 010306 general physics 0210 nano-technology Electron paramagnetic resonance Hyperfine structure Den kondenserade materiens fysik |
Popis: | The negative silicon vacancy (V-Si(-)) in SiC has recently emerged as a promising defect for quantum communication and room-temperature quantum sensing. However, its electronic structure is still not well characterized. While the isolated Si vacancy is expected to give rise to only two paramagnetic centers corresponding to two inequivalent lattice sites in 4H-SiC, there have been five electron paramagnetic resonance (EPR) centers assigned to V-Si(-) in the past: the so-called isolated no-zero-field splitting (ZFS) V-Si(-) center and another four axial configurations with small ZFS: T-V1a, T-V2a, T-V1b, and T-V2b. Due to overlapping with Si-29 hyperfine (hf) structures in EPR spectra of natural 4H-SiC, hf parameters of T-V1a have not been determined. Using isotopically enriched 4H-(SiC)-Si-28, we overcome the problems of signal overlapping and observe hf parameters of nearest C neighbors for all three components of the S = 3/2 T-V1a and T-V2a centers. The obtained EPR data support the conclusion that only T-V1a and T-V2a are related to V-Si(-) and the two configurations of the so-called isolated no-ZFS V-Si(-) center, V-Si(-) (I) and V-Si(-) (II), are actually the central lines corresponding to the transition I-1/2 amp;lt;-amp;gt; I + 1/2 of the T-V2a and T-V1a centers, respectively. Funding Agencies|Swedish Research Council [VR 2016-04068, VR 2016-05362]; Carl Trygger Stiftelse for Vetenskaplig Forskning [CTS 15:339]; Swedish Energy Agency [43611-1]; JSPS KAKENHI [A 17H01056] |
Databáze: | OpenAIRE |
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