Regensburg 2019 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 26: Focus Session: Quantum light sources for applications in quantum communication networks

HL 26.4: Talk

Wednesday, April 3, 2019, 10:45–11:00, H34

Optical properties of qubit centers in SiC — •Michel Bockstedte — Chemistry and Physics of Materials, University of Salzburg, Salzburg, Austria — Solid State Theory, Friedrich-Alexander-Universität Erlangen-Nürnberg

Several defect centers in silicon carbid represent quantum bits for applications like quantum sensing or can be employed as single photon emitters. The excited defect states and the photons emitted in transitions between them and the groundstate alongside spin-selective, non-radiative transitions via intermediate low-spin states are pivotal parts of the mechanism underlying qubit applications. Optical excitation of the qubit may also lead to an ionization into other charge states in which the qubit is silent. The ability to control and deliberately switch the charge state is pivotal for applications and has recently been explored in experiments [1]. However, the charge states actually involved in the switching and their optical properties are often not clear. Here we investigate the optical ionization of the divacancy and the silicon vacany within the frame work of the CI-CRPA approach [2]. We shine light onto ionizing single and two-photon processes. Our results show that an enhanced ionization cross section can occure for photon energies well above the ionization thresholds. This determines the charge state yielded by the ionization.
Golter and Lai, Sci. Reports 7, 13406 (2017).
Bockstedte et al. njp Quantum Materials 3, 31 (2018).