APS March Meeting 2017
Volume 62, Number 4
Monday–Friday, March 13–17, 2017;
New Orleans, Louisiana
Session K22: Spins in Solids for Quantum Information Processing
8:00 AM–11:00 AM,
Wednesday, March 15, 2017
Room: New Orleans Theater A
Sponsoring
Unit:
GQI
Chair: David Awschalom, University of Chicago
Abstract ID: BAPS.2017.MAR.K22.3
Abstract: K22.00003 : Realising a 2 Qubit Gate in Silicon with Donor Electron Spins
9:12 AM–9:48 AM
Preview Abstract
Abstract
Author:
Michelle Simmons
(UNSW, Sydney Australia)
Extremely long electron spin coherence times have recently been demonstrated
in isotopically pure Si-28 [1] making silicon one of the most promising
semiconductor materials for spin based quantum information. The two level
spin state of single electrons bound to shallow phosphorus donors in silicon
in particular provide well defined, reproducible qubits [2] and represent a
promising system for a scalable quantum computer in silicon. An important
challenge in these systems is the realisation of a two-qubit gate, where we
can both position donors with respect to each other for controllable
exchange coupling and with respect to charge sensors for individually
addressing and reading out the spin state of each donor with high fidelity.
To date we have demonstrated using scanning tunneling microscope hydrogen
lithography how we can precisely position individual P donors in Si [3]
aligned with nanoscale precision to local control gates [4] and can
initialize, manipulate, and read-out the spin states [5,6] with high
fidelity. We now demonstrate how we can achieve record single-electron
readout fidelity for each of two donor based dots of 99.8$\backslash ${\%},
above the surface-code fault tolerant threshold. We show how by engineering
the quantum dots to contain multiple donors we can achieve spin lifetimes up
to 16 times longer than single donors. Finally we show how by optimising the
interdonor separation and using asymmetric confinement potentials we can
create controllable exchange coupling in these devices. With the recent
demonstration of ultra-low noise in these all epitaxial devices [7] these
results confirm the enormous potential of atomic-scale qubits in silicon.\\
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$[1]$ J. T. Muhonen et al., Nature Nanotechnology 9, 986 (2014).\newline
[2] B.E. Kane, Nature 393, 133 (1998).\newline
[3] M. Fuechsle et al., Nature Nanotechnology 7, 242 (2012).\newline
[4] B. Weber et al., Science 335, 6064 (2012).\newline
[5] H. Buch et al., Nature Communications 4, 2017 (2013).\newline
[6] T.F. Watson et al., Physical Review Letters 115, 166806 (2015).\newline
[7] S. Shamim et al., Nano Letters 16, 5779 (2016).
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2017.MAR.K22.3