TY  - JOUR
A1  - Anisimov, A. N.
A1  - Simin, D.
A1  - Soltamov, V. A.
A1  - Lebedev, S. P.
A1  - Baranov, P. G.
A1  - Astakhov, G. V.
A1  - Dyakonov, V.
T1  - Optical thermometry based on level anticrossing in silicon carbide
JF  - Scientific Reports
N2  - We report a giant thermal shift of 2.1 MHz/K related to the excited-state zero-field splitting in the silicon vacancy centers in 4H silicon carbide. It is obtained from the indirect observation of the optically detected magnetic resonance in the excited state using the ground state as an ancilla. Alternatively, relative variations of the zero-field splitting for small temperature differences can be detected without application of radiofrequency fields, by simply monitoring the photoluminescence intensity in the vicinity of the level anticrossing. This effect results in an all-optical thermometry technique with temperature sensitivity of 100 mK/Hz\(^{1/2}\) for a detection volume of approximately 10\(^{−6}\) mm\(^3\). In contrast, the zero-field splitting in the ground state does not reveal detectable temperature shift. Using these properties, an integrated magnetic field and temperature sensor can be implemented on the same center.
KW  - electronic and spintronic devices
KW  - electronic properties and materials
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-147809
VL  - 6
IS  - 33301
ER  - 
TY  - JOUR
A1  - Simin, D.
A1  - Soltamov, V. A.
A1  - Poshakinskiy, A. V.
A1  - Anisimov, A. N.
A1  - Babunts, R. A.
A1  - Tolmachev, D. O.
A1  - Mokhov, E. N.
A1  - Trupke, M.
A1  - Tarasenko, S. A.
A1  - Sperlich, A.
A1  - Baranov, P. G.
A1  - Dyakonov, V.
A1  - Astakhov, G. V.
T1  - All-Optical dc Nanotesla Magnetometry Using Silicon Vacancy Fine Structure in Isotopically Purified Silicon Carbide
JF  - Physical Review X
N2  - We uncover the fine structure of a silicon vacancy in isotopically purified silicon carbide (4H-\(^{28}\)SiC) and reveal not yet considered terms in the spin Hamiltonian, originated from the trigonal pyramidal symmetry of this spin-3/2 color center. These terms give rise to additional spin transitions, which would be otherwise forbidden, and lead to a level anticrossing in an external magnetic field. We observe a sharp variation of the photoluminescence intensity in the vicinity of this level anticrossing, which can be used for a purely all-optical sensing of the magnetic field. We achieve dc magnetic field sensitivity better than 100  nT/√Hz within a volume of 3×10\(^{−7}\)mm\(^3\) at room temperature and demonstrate that this contactless method is robust at high temperatures up to at least 500 K. As our approach does not require application of radio-frequency fields, it is scalable to much larger volumes. For an optimized light-trapping waveguide of 3  mm\(^3\), the projection noise limit is below 100  fT/√Hz.
KW  - condensed matter physics
KW  - optoelectronics
KW  - spintronics
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-147682
VL  - 6
ER  -