Accession Number:

ADA499325

Title:

Solid State Quantum Computer in Silicon

Descriptive Note:

Final rept. 1 Jul 2004-30 Jun 2008

Corporate Author:

NEW SOUTH WALES UNIV SYDNEY (AUSTRALIA) RESEARCH OFFICE GRANTS SUPPORT SECTION

Report Date:

2008-09-30

Pagination or Media Count:

47.0

Abstract:

A SiP electron-spin qubit architecture was developed in 2008, based upon research outcomes over the four-year QCCM grant. Single-shot spin readout will proceed via spin-dependent tunneling to a Si MOS rf-SET, which we have demonstrated to posses charge sensitivities equal to or better than Al rf-SETs. Spin manipulation will occur using local electron-spin resonance ESR, which we have used to observe hyperfine-split electron spin resonances in P-doped Si MOSFETs. This spin qubit concept has been incorporated into the bi-linear array quantum computer design developed in parallel over 2004-2008 by the theory programs, which was one of the first quantum computer architectures quantitatively analyzed for the fault-tolerant threshold. Preliminary measurements on ion-implanted spin qubit devices have demonstrated transfer of P-donor electrons to a Si-SET detector with a large signal of 0.2e, while tunneling structures have enabled transport spectroscopy of singly occupied D0 and doubly occupied D- P-donor electron states. These measurements are strongly supported by the NEMO-TCAD program allowing donor species and position to be determined through transport spectroscopy. Single-ion implantation using on-chip PIN detectors now routinely produces SiP devices with accurately positioned single donors, such as a 2-P-atom charge qubit device, in which electron transfer events and charge-state relaxation times have been measured. Using STM atom-scale lithography the narrowest conducting doped wires in silicon have been demonstrated and used to fabricate the first in-plane-gated dot architecture. Measurements of these dots highlight the stability of in-plane gates compared with top gates and provide a pathway to atomically precise single donor architectures. Ab-initio and self-consistent tight-binding approaches have made progress in describing the essential physics of these highlydoped nanostructures.

Subject Categories:

  • Inorganic Chemistry
  • Crystallography
  • Quantum Theory and Relativity
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE