title: Spin blockade and exchange in Coulomb-confined silicon double quantum dots.
abstract: Electron spins confined to phosphorus donors in silicon are promising candidates as qubits because of their long coherence times, exceeding seconds in isotopically purified bulk silicon. With the recent demonstrations of initialization, readout and coherent manipulation of individual donor electron spins, the next challenge towards the realization of a Si:P donor-based quantum computer is the demonstration of exchange coupling in two tunnel-coupled phosphorus donors. Spin-to-charge conversion via Pauli spin blockade, an essential ingredient for reading out individual spin states, is challenging in donor-based systems due to the inherently large donor charging energies (∼45 meV), requiring large electric fields (>1 MV m(-1)) to transfer both electron spins onto the same donor. Here, in a carefully characterized double donor-dot device, we directly observe spin blockade of the first few electrons and measure the effective exchange interaction between electron spins in coupled Coulomb-confined systems.
authors.affiliation: Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia.
authors.forename: Bent
authors.initials: B
authors.lastname: Weber
authors.affiliation: Network for Computational Nanotechnology, Birck Nanotechnology Center, Purdue University, 1205 West State Street, West Lafayette, Indiana 47907, USA.
authors.forename: Y H Matthias
authors.initials: YH
authors.lastname: Tan
authors.affiliation: 1] Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia [2].
authors.forename: Suddhasatta
authors.initials: S
authors.lastname: Mahapatra
authors.affiliation: Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Watson
authors.affiliation: National Institute of Supercomputing and Networking, Korea Institute of Science and Technology Information, 245 Daehak-ro, Yuseong-gu, Daejeon 305-806, South Korea.
authors.forename: Hoon
authors.initials: H
authors.lastname: Ryu
authors.affiliation: Network for Computational Nanotechnology, Birck Nanotechnology Center, Purdue University, 1205 West State Street, West Lafayette, Indiana 47907, USA.
authors.forename: Rajib
authors.initials: R
authors.lastname: Rahman
authors.affiliation: Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Lloyd C L
authors.initials: LC
authors.lastname: Hollenberg
authors.affiliation: Network for Computational Nanotechnology, Birck Nanotechnology Center, Purdue University, 1205 West State Street, West Lafayette, Indiana 47907, USA.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Klimeck
authors.affiliation: Centre of Excellence for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia.
authors.forename: Michelle Y
authors.initials: MY
authors.lastname: Simmons
mesh_terms: D045663:Quantum Dots; D012825:Silicon / Q000737:chemistry*
chemical_list: D012825:Silicon
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