Flicker (1/f) noise in the critical current of Josephson junctions at 0.09–4.2 K

Wellstood, F. C.; Urbina, C.; Clarke, John
November 2004
Applied Physics Letters;11/29/2004, Vol. 85 Issue 22, p5296
Academic Journal
We have measured the low-frequency noise in the critical current Ic of six dc superconducting quantum interference devices (SQUIDs) with resistively shunted Nb–NbOx–PbIn Josephson junctions in the temperature range T=0.09–4.2 K. Each device is voltage biased, the applied flux is an integer number of flux quanta, and the current fluctuations are measured with a second dc SQUID. At low frequencies f, there is a component of the power spectrum of the critical current fluctuations given approximately by SIc(f)=CIc2T2/Af, where A is the area of both junctions, and C≈(3.9±0.4)×10-23 m2/K2. For quantum bits based on Josephson junctions, the scaling of SIc(f) with T2 implies that the dephasing time limited by critical current l/f noise should scale as 1/T for temperatures down to at least 0.09 K.


Related Articles

  • Quantum-displacement detection: SQUIDs at the limit. Blencowe, Miles P. // Nature Physics;Oct2008, Vol. 4 Issue 10, p753 

    The article discusses the superconducting quantum interference devices (SQUIDs). It mentions that SQUID has superconducting wire loop called Josephson junctions. In addition, SQUIDs are used as amplifying displacements to detect the low-temperature resonator. According to the author, the...

  • Structurally asymmetric d.c. SQUID’s in the presence of coupling energy inhomogeneity of the junctions studied by means of the reduced two-junction interferometer model. De Luca, R.; Romeo, F. // European Physical Journal B -- Condensed Matter;Feb2005, Vol. 43 Issue 4, p445 

    The effects of structural asymmetries and of inhomogeneities in the junction parameters on the electrodynamic response of conventional d.c. SQUID’s are studied both analytically and numerically. By a first-order perturbative expansion with respect to the parameter ß and to the...

  • The influence of the second harmonic in the current-phase relation on the voltage-current characteristic of high TC DC SQUID. Greenberg, Ya. S; Novikov, I. L.; Schultze, V.; Meyer, H. G. // European Physical Journal B -- Condensed Matter;Mar2005, Vol. 44 Issue 1, p57 

    A theory for the voltage-current characteristic in high TC DC SQUIDs (Superconducting Quantum Interference Devices), which accounts for a second harmonic in the junction current-phase relation, is developed. It is shown that the small inductance DC SQUIDs can be used for the investigation of the...

  • Dynamic properties of a superconducting quantum interference device containing arrays of Josephson junctions. Darula, M.; Seidel, P.; Busse, F.; Benˇacˇka, Sˇ. // Journal of Applied Physics;8/15/1993, Vol. 74 Issue 4, p2674 

    Presents information on a study which analyzed the dynamic properties of a superconducting quantum interference device (SQUID) containing arrays of Josephson junctions in a superconducting loop. Modeling of many junction SQUID; Static characteristics of SQUID; Conclusions.

  • Penetration depth of MgB2 measured using Josephson junctions and SQUIDs. Cunnane, Daniel; Zhuang, Chenggang; Chen, Ke; Xi, X. X.; Yong, Jie; Lemberger, T. R. // Applied Physics Letters;2/18/2013, Vol. 102 Issue 7, p072603 

    The penetration depth of MgB2 was measured using two methods of different mechanisms. The first method used MgB2 Josephson junctions and the magnetic field dependence of the junction critical current. The second method deduced the penetration depth from the inductance of a MgB2 microstrip used...

  • Controlled-junction superconducting quantum interference device via phonon injection. Hutchinson, G. D.; Qin, H.; Hasko, D. G.; Kang, D. J.; Williams, D. A. // Applied Physics Letters;1/5/2004, Vol. 84 Issue 1, p136 

    The direct current superconducting quantum interference device (DC-SQUID), using controlled Josephson junction technology, provides a mechanism to modify the characteristics of the device post-fabrication. We report on the fabrication and measurement of a micron sized DC-SQUID using two Dayem...

  • The Ultimate Sensitivity of a High-Temperature Microwave SQUID Magnetometer Operating in the Hysteresis Regime. Vendik, O.G.; Danilov, I.S. // Technical Physics;Mar2002, Vol. 47 Issue 3, p330 

    Focuses on a study which developed a method for the determination of the noise spectral density in a high-temperature microwave superconducting quantum interference device (SQUID) operating in the hysteresis regime. Background on SQUID; Intrinsic noise of the measuring system; Noise of the...

  • Noise properties of direct current SQUIDS with quasiplanar YBa[sub 2]Cu[sub 3]O[sub 7] Josephson.... Faley, M.I.; Poppe, U. // Applied Physics Letters;10/2/1995, Vol. 67 Issue 14, p2087 

    Describes the noise direct current (dc) superconducting quantum interference devices (SQUID) with quasiplanar ramp-type Josephson junctions. Measurement of the noise spectrum of dc SQUID; Influence of magnetic flux, bias current, high static magnetic field and aging on SQUID; Observation of the...

  • Low noise YBa2Cu3O7-δ grain boundary junction dc SQUIDs. Gross, R.; Chaudhari, P.; Kawasaki, M.; Ketchen, M. B.; Gupta, A. // Applied Physics Letters;8/13/1990, Vol. 57 Issue 7, p727 

    We have fabricated YBa2Cu3O7-δ grain boundary junction dc superconducting quantum interference devices (SQUIDs) with a square washer geometry design. The SQUIDs were formed in c-axis oriented epitaxial films with a single grain boundary of predetermined nature. These SQUIDs show perfectly...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics