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Energetic Suppression of Decoherence in Exchange-Only Quantum Computation

Yaakov S. Weinstein·C. Stephen Hellberg
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Abstract

Universal quantum computation requiring only the Heisenberg exchange interaction and suppressing decoherence via an energy gap is presented. The combination of an always-on exchange interaction between the three physical qubits comprising the encoded qubit and a global magnetic field generates an energy gap between the subspace of interest and all other states. This energy gap suppresses decoherence. Always-on exchange couplings greatly simplify hardware specifications and the implementation of inter-logical-qubit gates. A controlled phase gate can be implemented using only three Heisenberg exchange operations all of which can be performed simultaneously.

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Yaakov S. Weinstein, C. Stephen Hellberg. 2004-08-05. Energetic Suppression of Decoherence in Exchange-Only Quantum Computation. https://doi.org/10.1103/physreva.72.022319

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