Transferring multiqubit entanglement onto memory qubits in a decoherence-free subspace
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- 作者：Xiao-Ling He ; Chui-Ping Yang
- 关键词：GHZ state transfer ; Entanglement ; Operation qubit ; Memory qubit ; Decoherence ; free subspace ; Dephasing ; Cavity or circuit QED
- 刊名：Quantum Information Processing
- 出版年：2017
- 出版时间：March 2017
- 年：2017
- 卷：16
- 期：3
- 全文大小：
- 刊物类别：Physics and Astronomy
- 刊物主题：Quantum Information Technology, Spintronics; Quantum Computing; Data Structures, Cryptology and Information Theory; Quantum Physics; Mathematical Physics;
- 出版者：Springer US
- ISSN：1573-1332
- 卷排序：16
文摘
Different from the previous works on generating entangled states, this work is focused on how to transfer the prepared entangled states onto memory qubits for protecting them against decoherence. We here consider a physical system consisting of n operation qubits and 2n memory qubits placed in a cavity or coupled to a resonator. A method is presented for transferring n-qubit Greenberger–Horne–Zeilinger (GHZ) entangled states from the operation qubits (i.e., information processing cells) onto the memory qubits (i.e., information memory elements with long decoherence time). The transferred GHZ states are encoded in a decoherence-free subspace against collective dephasing and thus can be immune from decoherence induced by a dephasing environment. In addition, the state transfer procedure has nothing to do with the number of qubits, the operation time does not increase with the number of qubits, and no measurement is needed for the state transfer. This proposal can be applied to a wide range of hybrid qubits such as natural atoms and artificial atoms (e.g., various solid-state qubits).