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Published on: November 11, 2013
Charge-fluctuation-induced dephasing of exchange-coupled spin qubits
1Department of Physics, University at Buffalo, The State University of New York, 239 Fronczak Hall, Buffalo, New York 14260-1500, USA.
Abstract:
Exchange-coupled spin qubits in semiconductor nanostructures are shown to be vulnerable to dephasing caused by charge noise invariably present in the semiconductor environment. This decoherence of exchange gate by environmental charge fluctuations arises from the fundamental Coulombic nature of the Heisenberg coupling and presents a serious challenge to the scalability of the widely studied exchange gate solid state spin quantum computer architectures. We estimate dephasing times for coupled spin qubits in a wide range (from 1 ns up to >1 micros) depending on the exchange coupling strength and its sensitivity to charge fluctuations.
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