通过态层析成像测量两个超导量子比特的纠缠度

Measurement of the entanglement of two superconducting qubits via state tomography.

作者信息

Steffen Matthias, Ansmann M, Bialczak Radoslaw C, Katz N, Lucero Erik, McDermott R, Neeley Matthew, Weig E M, Cleland A N, Martinis John M

机构信息

Department of Physics and California Nano Systems Institute, University of California, Santa Barbara, CA 93106, USA.

出版信息

Science. 2006 Sep 8;313(5792):1423-5. doi: 10.1126/science.1130886.

DOI:10.1126/science.1130886

PMID:16960003

Abstract

Demonstration of quantum entanglement, a key resource in quantum computation arising from a nonclassical correlation of states, requires complete measurement of all states in varying bases. By using simultaneous measurement and state tomography, we demonstrated entanglement between two solid-state qubits. Single qubit operations and capacitive coupling between two super-conducting phase qubits were used to generate a Bell-type state. Full two-qubit tomography yielded a density matrix showing an entangled state with fidelity up to 87%. Our results demonstrate a high degree of unitary control of the system, indicating that larger implementations are within reach.

摘要

量子纠缠是量子计算中的关键资源，源于态的非经典关联，其演示需要在不同基下对所有态进行完整测量。通过同时进行测量和态层析成像，我们演示了两个固态量子比特之间的纠缠。利用单量子比特操作以及两个超导相位量子比特之间的电容耦合来生成一个贝尔型态。完整的双量子比特层析成像得到了一个密度矩阵，显示出保真度高达87%的纠缠态。我们的结果表明对该系统有高度的幺正控制，这表明更大规模的实现是可行的。