A trapped-ion-based quantum byte with 10(-5) next-neighbour cross-talk

作者：Piltz C; Sriarunothai T; Varon A F; Wunderlich C^*

来源：Nature Communications, 2014, 5(1): 4679.

DOI：10.1038/ncomms5679

The addressing of a particular qubit within a quantum register is a key pre-requisite for scalable quantum computing. In general, executing a quantum gate with a single qubit, or a subset of qubits, affects the quantum states of all other qubits. This reduced fidelity of the whole-quantum register could prevent the application of quantum error correction protocols and thus preclude scalability. Here we demonstrate addressing of individual qubits within a quantum byte (eight qubits) and measure the error induced in all non-addressed qubits (cross-talk) associated with the application of single-qubit gates. The quantum byte is implemented using microwave-driven hyperfine qubits of Yb-171(+) ions confined in a Paul trap augmented with a magnetic gradient field. The measured cross-talk is on the order of 10 (-5) and therefore below the threshold commonly agreed sufficient to efficiently realize fault-tolerant quantum computing. Hence, our results demonstrate how this threshold can be overcome with respect to cross-talk.

• 出版日期2014-8