Experimental demonstration of a robust and scalable flux qubit

被引：135

作者：

Harris, R. ^{[1
]}

Johansson, J. ^{[1
]}

Berkley, A. J. ^{[1
]}

Johnson, M. W. ^{[1
]}

Lanting, T. ^{[1
]}

Han, Siyuan ^{[2
]}

Bunyk, P. ^{[1
]}

Ladizinsky, E. ^{[1
]}

Oh, T. ^{[1
]}

Perminov, I. ^{[1
]}

Tolkacheva, E. ^{[1
]}

Uchaikin, S. ^{[1
]}

Chapple, E. M. ^{[1
]}

Enderud, C. ^{[1
]}

Rich, C. ^{[1
]}

Thom, M. ^{[1
]}

Wang, J. ^{[1
]}

Wilson, B. ^{[1
]}

Rose, G. ^{[1
]}

机构：

[1] D Wave Syst, Burnaby, BC V5C 6G9, Canada

[2] Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA

来源：

PHYSICAL REVIEW B | 2010年 / 81卷 / 13期

关键词：

PERSISTENT-CURRENT QUBIT; QUANTUM SUPERPOSITION; COMPUTATION; DYNAMICS; STATES; NOISE;

D O I：

10.1103/PhysRevB.81.134510

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

A rf-superconducting quantum interference device (SQUID) flux qubit that is robust against fabrication variations in Josephson-junction critical currents and device inductance has been implemented. Measurements of the persistent current and of the tunneling energy between the two lowest-lying states, both in the coherent and incoherent regimes, are presented. These experimental results are shown to be in agreement with predictions of a quantum-mechanical Hamiltonian whose parameters were independently calibrated, thus justifying the identification of this device as a flux qubit. In addition, measurements of the flux and critical current noise spectral densities are presented that indicate that these devices with Nb wiring are comparable to the best A1 wiring rf SQUIDs reported in the literature thus far, with a 1/f flux noise spectral density at 1 Hz of 1.3(-0.5)(+0.7) mu Phi(0)/root Hz. An explicit formula for converting the observed flux noise spectral density into a free-induction-decay time for a flux qubit biased to its optimal point and operated in the energy eigenbasis is presented.

引用

页数：19

共 61 条

[31] Dephasing of a superconducting flux qubit [J].