Entangled macroscopic quantum states in two superconducting qubits

被引:394
作者
Berkley, AJ [1 ]
Xu, H [1 ]
Ramos, RC [1 ]
Gubrud, MA [1 ]
Strauch, FW [1 ]
Johnson, PR [1 ]
Anderson, JR [1 ]
Dragt, AJ [1 ]
Lobb, CJ [1 ]
Wellstood, FC [1 ]
机构
[1] Univ Maryland, Ctr Superconduct Res, Dept Phys, College Pk, MD 20742 USA
关键词
D O I
10.1126/science.1084528
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
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 gigahertz range 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.
引用
收藏
页码:1548 / 1550
页数:3
相关论文
共 22 条
  • [11] ENERGY-LEVEL QUANTIZATION IN THE ZERO-VOLTAGE STATE OF A CURRENT-BIASED JOSEPHSON JUNCTION
    MARTINIS, JM
    DEVORET, MH
    CLARKE, J
    [J]. PHYSICAL REVIEW LETTERS, 1985, 55 (15) : 1543 - 1546
  • [12] Coherent control of macroscopic quantum states in a single-Cooper-pair box
    Nakamura, Y
    Pashkin, YA
    Tsai, JS
    [J]. NATURE, 1999, 398 (6730) : 786 - 788
  • [13] Nielsen M. A., 2001, QUANTUM COMPUTATION
  • [14] Quantum oscillations in two coupled charge qubits
    Pashkin, YA
    Yamamoto, T
    Astafiev, O
    Nakamura, Y
    Averin, DV
    Tsai, JS
    [J]. NATURE, 2003, 421 (6925) : 823 - 826
  • [15] Design for effective thermalization of junctions for quantum coherence
    Ramos, RC
    Gubrud, MA
    Berkley, AJ
    Anderson, JR
    Lobb, CJ
    Wellstood, FC
    [J]. IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 2001, 11 (01) : 998 - 1001
  • [16] RAMOS RC, IN PRESS IEEE T APPL
  • [17] Tinkham M., 1995, INTRO SUPERCONDUCTIV
  • [18] Quantum superposition of macroscopic persistent-current states
    van der Wal, CH
    ter Haar, ACJ
    Wilhelm, FK
    Schouten, RN
    Harmans, CJPM
    Orlando, TP
    Lloyd, S
    Mooij, JE
    [J]. SCIENCE, 2000, 290 (5492) : 773 - 777
  • [19] Manipulating the quantum state of an electrical circuit
    Vion, D
    Aassime, A
    Cottet, A
    Joyez, P
    Pothier, H
    Urbina, C
    Esteve, D
    Devoret, MH
    [J]. SCIENCE, 2002, 296 (5569) : 886 - 889
  • [20] MACROSCOPIC QUANTUM TUNNELING IN 1-MU-M NB JOSEPHSON-JUNCTIONS
    VOSS, RF
    WEBB, RA
    [J]. PHYSICAL REVIEW LETTERS, 1981, 47 (04) : 265 - 268