Berlin 2015 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 105: Quantum Information Systems: Si Vacancies and NV Centers (jointly with HL)

TT 105.2: Talk

Thursday, March 19, 2015, 15:15–15:30, ER 164

SiC nano-crystalline NIR emitters based on optically excited and spin polarized defects — •F. Fuchs¹, A. Muzha², N. Tarakina^3,4, D. Simin¹, M. Trupke⁵, P. Baranov⁶, V. Dyakonov^1,3,7, A. Krueger^2,3, and G. Astakhov¹ — ¹Exp. Physics VI, University of Würzburg — ²Institute of Organic Chemistry, University of Würzburg — ³Wilhelm Conrad Röntgen RCCM, University of Würzburg — ⁴Exp. Physics III, University of Würzburg — ⁵Vienna Center for Quantum Science and Technology, TU Wien — ⁶Ioffe Institute, St. Petersburg — ⁷ZAE Bayern, Würzburg

The unification of luminescent markers for bioimaging and spin centers for quantum sensing [1] is challenging; especially when aiming for the ideal NIR window, stability and non-toxicity. Bulk silicon carbide (SiC) is a favored candidate despite its large band gap, which we could mitigate by the introduction of silicon vacancy defects—exhibiting NIR emission—via neutron irradiation. With a milling procedure, we fabricated SiC nano crystals ranging from 600nm down to 60nm in size, with a further fragmentation of the latter into clusters of high crystalline quality (size ca. 10 nm) separated by amorphous material. The luminescence of the vacancies persists in all size fractions, moreover, we detected room-temperature spin resonance [2]. This leads to new perspectives: defects in nano crystalline SiC as in-vivo luminescent markers and simultaneously as magnetic field or temperature sensors [3].

[1] Riedel et al.: Phys. Rev. Lett. 109, 22 (2012)

[2] Fuchs et al. arXiv: 1409.0756v1

[3] Kraus et al.: Sci. Rep. 4, 5303 (2014)