Chih-Hwan Henry Yang

Silicon quantum dot qubits for quantum information processing

Silicon quantum dots (QDs) have become a field of significant interest for quantum information processing, due to the long spin coherence times possible in isotopically purified silicon and their compatibility with modern industrial technology. In this talk I will discuss the evolution of silicon MOS based silicon QDs at UNSW Australia. This includes fabrication and transport studies of our QDs [1, 2], electron charge state detection [3], spin-valley physics in QDs [4-6], realisation of a spin qubit using an integrated electron spin resonance line [7], and a two qubit system with CNOT and CZ gate control [8]. Our results show that Si-MOS QD qubits can have relaxation times T1 exceeding 2 seconds, and coherence times T2 of 28 milliseconds, and that the device architecture enables control over both the electron gyromagnetic ratio and the valley splitting energy.

[1] S. J. Angus et al., Nano Letters 7, 2051 (2007)
[2] W. H. Lim et al., Appl. Phys. Lett. 95, 242102 (2009)
[3] C. H. Yang et al., AIP Advances 1, 042111 (2011)
[4] W. H. Lim et al., Nanotechnology 22, 335704 (2011)
[5] C. H. Yang et al., Phys. Rev. B 86, 115319 (2012)
[6] C. H. Yang et al., Nature Comm. 4, 2069 (2013)
[7] M. Veldhorst et al., Nature Nano. 9, 981 (2014)
[8] M. Veldhorst et al., Nature 526, 410 (2015)

Institut Quantique
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