2004/02/06 by Marek Šašura, Marek Sasura, Andrew Steane +2
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Physics (quant-ph) #Quantum and electron transport phenomena #quant-ph
paper · pdf · doi:10.48550/arxiv.quant-ph/0402054
12 pages, 5 figures
arxiv created 2004/02/06 · openalex publication_date 2004/02/06 · arxiv updated 2016/09/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider quantum gates for trapped ions using state-selective displacement of the ions. We generalize earlier work in order to treat arbitrary separations between the traps. This requires the impact of anharmonicity arising from the Coulomb interaction to be estimated. We show that its effects are always small enough to allow high fidelity. In particular, the method can be applied to two ions in the same trap. We also show that gates between non-neighbour ions, and hence a Toffoli (three-qubit controlled-NOT) gate, can be achieved. We discuss how the gate can be applied to logical qubits encoded in the decoherence-free-subspace |01>,|10>, where each pair of ions stores a single qubit. We also suggest alternatives to the spin-echo method to suppress unwanted terms in the evolution.