McCamey, D.R. et al., Science 330, 16521656 (2010). [5]. Stoneham, A.M. et al., Journal of PhysicsCondensed Matter 21, 364222 (2009). [6]. Stoneham, A.J. et ...
NATIONAL HIGH MAGNETIC FIELD LABORATORY 2010 RESEARCH REPORT
The Initialization and Manipulation of Quantum Information Stored in Silicon by Bismuth Dopants Gavin W Morley, Marc Warner, A Marshall Stoneham, P Thornton Greenland (University College London, Physics and London Centre for Nanotechnology); Johan van Tol (NHMFL and FSU, Chem.); Christopher W M Kay (University College London, London Centre for Nanotechnology and Institute of Structural and Molecular Biology); Gabriel Aeppli (University College London, Physics and London Centre for Nanotechnology) Magnetic Field (T)
Introduction
We used the pulsed electron magnetic resonance (EMR) spectrometer developed at the NHMFL [10, 11], as well as a Bruker E580 in UCL.
Results and Discussion
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CW EPR signal (arb. units)
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Experimental
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Energy (GHz)
High magnetic fields can be used to polarize spin qubits, initializing them for a quantum computation [1 4]. Phosphorus dopants in silicon (Si:P) are a leading candidate for these applications, but heavier impurities such as bismuth in silicon (Si:Bi) could be used in conjunction with Si:P for quantum information proposals that require two separately addressable spin species [5, 6]. We have found that such schemes are indeed feasible as the electron spin coherence time (T2) of Si:Bi is at least 2 ms, which is longer than for Si:P with nonisotopically purified silicon [7, 8]. Si:Bi also presents novel opportunities for quantum information processing at low magnetic fields [9].
115 120 125 8.4
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Magnetic field (T) 209 Figure 1. EMR spectra of Si:Bi at 240 GHz with Figure 1 shows that the Bi nuclear spin can be simulations based on the energy levels shown. hyperpolarized at 3 K with a high magnetic field of 8.6 T, Adapted from reference [7]. in the presence of white light. We also demonstrated pulsed manipulation (not shown) of this nucleus with electronnuclear double resonance (ENDOR) at 8.6 T [7].
Conclusions We have found that bismuth atoms in silicon have long electron spin coherence times and we used high magnetic fields to polarize the electronic and nuclear spins of these qubits.
Acknowledgements This work was supported by the EPSRC COMPASSS grant and by the NHMFL through Visiting Scientist Program grant #12488. GWM acknowledges support from the Royal Commission for the Exhibition of 1851.
References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
Morley, G.W. et al., Phys. Rev. Lett. 98, 220501 (2007). Morley, G.W. et al., Phys. Rev. Lett. 101, 207602 (2008). McCamey, D.R, et al., Phys. Rev. Lett. 102, 027601 (2009). McCamey, D.R. et al., Science 330, 16521656 (2010). Stoneham, A.M. et al., Journal of PhysicsCondensed Matter 21, 364222 (2009). Stoneham, A.J. et al., Journal of PhysicsCondensed Matter 15, L447 (2003). Morley G.W., et al., Nature Materials 9, 725 (2010). George R.E. et al., Phys. Rev. Lett. 105, 067601 (2010). Mohammady, M.H., et al., Phys. Rev. Lett. 105, 067602 (2010). Morley, G.W. et al., Review of Scientific Instruments 79, 064703 (2008). van Tol, J. et al., Review of Scientific Instruments 76, 074101 (2005).
