Dresden 2014 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 25: Focus Session: Electron Spin Qubits in Semiconductor Quantum Dots (organized by HL)

TT 25.11: Vortrag

Montag, 31. März 2014, 18:30–18:45, POT 051

Addressing ionized ⁷⁵As nuclear spin qubits in silicon using nuclear quadrupole interaction — •Florian M. Hrubesch, David P. Franke, Markus Künzl, Andrej Voss, Felix Hoehne, Lukas Dreher, and Martin S. Brandt — Walter Schottky Institut, Technische Universität München, Am Coulombwall 4, 85748 Garching

Electrically detected electron nuclear double resonance (EDENDOR) studies have shown coherence times of ³¹P⁺ nuclear spins in crystalline ^natSi of 18 ms [1]. In isotopically enriched ²⁸Si these T₂ times can reach up to 3 hours [2], making these nuclear spins promising candidates for quantum information storage. However, these long coherence times are caused by the nearly perfect isolation of the ionized donor nuclear spins from their environment, which hampers selective addressing with e.g. electric fields. We present EDENDOR measurements on ⁷⁵As⁺ nuclear spins in ^natSi which exhibit similarly long decoherence times as ³¹P⁺ nuclear spins in ^natSi. By applying elastic strain, the transition frequencies involving the |m_I|=3/2 states can be shifted by about 25 kHz, while the transitions between the |m_I|=1/2 states remain virtually unaffected. This allows the selective manipulation of the nuclear spin state via magnetic resonance, which could enable the addressing of single ⁷⁵As⁺ qubits with the help of nanoscale piezoactuators positioned on top of the donors [3]. [1] L. Dreher et al., Phys. Rev. Lett. 108, 027602 (2012) [2] K. Saeedi et al., Science 342, 830 (2013) [3] L. Dreher et al, Phys. Rev. Lett. 106, 037601 (2011)