Abstract

Silicon quantum dots (QDs) have becoming a field of interest in quantum information processing, with its long spin coherence time in isotopically purified silicon and compatibility with modern industrial technology. In this talk, I will cover the evolution of silicon MOS based silicon QDs in UNSW Australia. This includes fabrication of our QD [1, 2], electron charge detection [3], spin/valley physics of a QD [4-6], realisation of an electron spin resonant line controlled qubit device [7], and our recent work on a two qubit system [8]. Our results shown the Si-MOS QD qubits can exceed relaxation time, T1 over 2 seconds and coherence time, T2 over 28 milliseconds, and have control over the electron gyromagnetic ratio and 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., Nat. Comm. 4, 2069 (2013) [7] M. Veldhorst et al., Nat. Nano. 9, 981 (2014) [8] M. Veldhorst et al., arXiv:1411.5760