Donor-Based Silicon Quantum Computing
Abstract
This proposal summarizes the work plan and milestones for delivering high fidelity 1 and 2 qubit devices based on phosphorus (P) donors in silicon (Si) by researchers at the Australian Research Council Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) working with leading US groups including Purdue and Harvard University through separate sub-contracts. The program is supported by 50 personnel, including 7 Faculty, 18 postdoctoral/technical staff and 26 PhD students and seeks an average support of US$1.0m p.a. for 4 years. Australian sources of confirmed and pending support for the donor based silicon program of the CQC2T for the period 2011-17 total US$5.0m p.a. The proposed work plan builds on CQC2T s track record for the period 2010-2015, and in particular, on the unique strategy pioneered at UNSW to design, build and model devices in silicon with atomic precision. To date the results demonstrated by Professors Simmons, Rogge and Hollenberg have been documented in 570 of the 1378 Centre publications (over 40%) since 2000 (sec http://www.cqc2t.org/). Since 2012 this includes: the demonstration of the world s first single-atom transistor; the creation of atomic-scale wires in silicon to address qubit states; the first experimental measurement of qubit coupling and exchange between two precision-placed P atoms in Si; the highest fidelity spin initialisation and read-out of P in Si; and the direct measurement of the electron wave function and exact location of the P atom in Si. Together this team has recently published a full-scale architecture for an error-corrected quantum processor. The work plan, summarized in the flow-chart on page D-5 is coordinated with the CQC2T work plan submitted to the Australian Research Council for 2017-2024 and is broken down chronologically into the Milestone Tables on pages D6-D9. The program is focused on precision Si:P electron spin qubits, and includes investigations of the P nuclear spins to assess their role in single and multi-qubit operations. Key goals for Years 1-2 include the demonstration of high-fidelity 1- and 2- qubit gates for single-spin and singlet-triplet (S/T) qubit encoding on P donors in natSi. These devices will be characterized by randomised benchmarking with UNSW/ Harvard to help identify limiting noise sources. Studies will also be undertaken to increase the speed and sensitivity of read-out using RF-SETs and RF-SLQDs (single-lead quantum dots); to instigate growth programs in Si-28 at UNSW; and to identify and mitigate leading noise sources experimentally at UNSW and theoretically at Purdue and the University of Melbourne (UM). From Years 2 to Year 4 we aim to move to isotopically-pure Si-28 material and determine the effect this has on high-fidelity 1- and 2- gates. We will demonstrate 2 qubit CNOT gates with full process tomography and gate/error characterization. With Harvard/UM we will characterize 2 qubit gate fidelities of exchanged coupled qubits based on architectures developed in years 1&2 and analyze the cross-talk between neighbouring qubits during single & two qubit operations. In parallel we aim to demonstrate 2 capacitively coupled SIT qubits. Noise studies at UNSW will be used to optimize multi-qubit gate fidelities and coherence times. The overall aim at the end of Year 4 is the full characterization of a 2 qubit device with high fidelity (>99%) single and (>90%) two qubit gates.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2018
- Source ID
- W911NF1710202
Entities
People
- Michelle Simmons
Organizations
- Army Contracting Command
- National Security Agency
- University of New South Wales