Re-engineering the band gap of silicon and diamond with implanted ions
Prof. Dr. David N. Jamieson (School of Physics, University of Melbourne, Australia)

With the launch of the Quantum Manifesto by the EU and the National Strategic Innovation Agenda in Australia to include building a quantum computer device, along with other initiatives worldwide, the new field of quantum technology is driving major research programs. Within the Centre of Excellence for Quantum, Computation and Communication Technology, we have shown how it is now possible to fabricate devices [1-5] which exploit the internal quantum degrees of freedom of single atoms in the solid state with nuclear spin coherence times above 30 s [2]. These devices bridge the foundations of modern information technology based on silicon into the future of ultra-scaled devices where quantum mechanics offers new functionalities for sensing, information storage, information processing and secure data transmission guaranteed by the laws of Physics. Here we focus on the development of a technique [6] that employs shallow deterministic ion implantation, within 20 nm of the surface, which is compatible with the process flow for the fabrication of single atom semiconductor devices with the standard tools of the industry. We also apply the same technique to address the yet unsolved problem of deterministically engineering single colour centres in diamond, made possible now with the recent availability of ultra-pure synthetic diamond. We show that devices fabricated from this new material have exceptionally long carrier lifetimes [7]. Device architectures exploiting this technology could form the building blocks of near-term CMOS quantum devices fabricated with the standard tools of the semiconductor industry.

References:
[1] Bell's inequality violation with spins in silicon, JP Dehollain, et al., Nature Nanotechnology 11 p242 (2016)
[2] Storing quantum information for 30 seconds in a nanoelectronic device, JT Muhonen, et al. Nature Nanotechnology 9, p986 (2014)
[3] High-fidelity readout and control of a nuclear spin qubit in silicon, JJ Pla, et al., Nature 496, p334 (2013)
[4] A single-atom electron spin qubit in silicon, JJ Pla, et al., Nature 489, p541 (2012)
[5] Single-shot readout of an electron spin in silicon, A Morello, et al., Nature 467, p687 (2010)
[6] Single atom devices by ion implantation, JA van Donkelaar, et al., J. Phys. Cond. Mat. 27, 154204 (2015)
[7] A 3D lateral electrode structure for diamond based microdosimetry, JA Davis, et al., APL 110 013503 (2017)