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arXiv · 0806.0677

Topological degeneracy and decoherence-protected qubits in circuit QED

Gang Chen·Zheng-Yuan Xue·J. -Q. Liang
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Abstract

We introduce an extended Dicke model with controllable long-range atom-atom interaction to simulate topologically ordered states and achieve decoherence-protected qubits. We illustrate our idea in an experimentally feasible circuit quantum electrodynamics scenario. Due to the intrinsic competition with the atom-field coupling strength, we first demonstrate that this atom-atom interaction can exhibit a novel topological quantum interference effect arising from the instanton and anti-instanton tunneling paths. As a consequence, this proposed model only with a few odd-number of atoms has a two-fold absolute degenerate ground-subspace with a large energy gap, which can become larger with the increasing of the system-size. It may also support the excitation of anyonic statistics, and thus can be regarded as a possible candidate for processing topological quantum memory.

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Gang Chen, Zheng-Yuan Xue, J. -Q. Liang. 2008-06-04. Topological degeneracy and decoherence-protected qubits in circuit QED. https://arxiv.org/abs/0806.0677

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