1. |
- Gali, Ádám, et al.
(author)
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Point defects in SiC
- 2008
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Conference paper (peer-reviewed)abstract
- Tight control of defects is pivotal for semiconductor technology. However, even the basic defects are not entirely understood in silicon carbide. In the recent years significant advances have been reached in the identification of defects by combining the experimental tools like electron paramagnetic resonance and photoluminescence with ab initio calculations. We summarize these results and their consequences in silicon carbide based technology. We show recent methodological developments making possible the accurate calculation of absorption and emission signals of defects.
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2. |
- Szasz, Krisztian, et al.
(author)
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Spin and photophysics of carbon-antisite vacancy defect in 4H silicon carbide: A potential quantum bit
- 2015
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In: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 91:12, s. 121201-
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Journal article (peer-reviewed)abstract
- Silicon carbide with engineered point defects is considered as very promising material for the next generation devices, with applications ranging from electronics and photonics to quantum computing. In this context, we investigate the spin physics of the carbon antisite-vacancy pair that in its positive charge state enables a single photon source. We find by hybrid density functional theory and many-body perturbation theory that the neutral defect possesses a high spin ground state in 4H silicon carbide and provide spin-resonance signatures for its experimental identification. Our results indicate the possibility for the coherent manipulation of the electron spin by optical excitation of this defect at telecom wavelengths, and suggest the defect as a candidate for an alternative solid state quantum bit.
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3. |
- Widmann, Matthias, et al.
(author)
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Electrical Charge State Manipulation of Single Silicon Vacancies in a Silicon Carbide Quantum Optoelectronic Device
- 2019
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In: Nano letters (Print). - : AMER CHEMICAL SOC. - 1530-6984 .- 1530-6992. ; 19:10, s. 7173-7180
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Journal article (peer-reviewed)abstract
- Color centers with long-lived spins are established platforms for quantum sensing and quantum information applications. Color centers exist in different charge states, each of them with distinct optical and spin properties. Application to quantum technology requires the capability to access and stabilize charge states for each specific task. Here, we investigate charge state manipulation of individual silicon vacancies in silicon carbide, a system which has recently shown a unique combination of long spin coherence time and ultrastable spin-selective optical transitions. In particular, we demonstrate charge state switching through the bias applied to the color center in an integrated silicon carbide optoelectronic device. We show that the electronic environment defined by the doping profile and the distribution of other defects in the device plays a key role for charge state control. Our experimental results and numerical modeling evidence that control of these complex interactions can, under certain conditions, enhance the photon emission rate. These findings open the way for deterministic control over the charge state of spin-active color centers for quantum technology and provide novel techniques for monitoring doping profiles and voltage sensing in microscopic devices.
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