Publication Date:
2003-05-17
Description:
We present spectroscopic evidence for the creation of entangled macroscopic quantum states in two current-biased Josephson-junction qubits coupled by a capacitor. The individual junction bias currents are used to control the interaction between the qubits by tuning the energy level spacings of the junctions in and out of resonance with each other. Microwave spectroscopy in the 4 to 6 gigahertzrange at 20 millikelvin reveals energy levels that agree well with theoretical results for entangled states. The single qubits are spatially separate, and the entangled states extend over the 0.7-millimeter distance between the two qubits.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Berkley, A J -- Xu, H -- Ramos, R C -- Gubrud, M A -- Strauch, F W -- Johnson, P R -- Anderson, J R -- Dragt, A J -- Lobb, C J -- Wellstood, F C -- New York, N.Y. -- Science. 2003 Jun 6;300(5625):1548-50. Epub 2003 May 15.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Superconductivity Research, Department of Physics, University of Maryland, College Park, MD 20742, USA. berkley@physics.umd.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12750479" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
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Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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