Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Superconductor Science and Technology

Noise measurements in a two-hole radio frequency SQUID at liquid-nitrogen temperature

S.P. Harrop, Colin E Gough, Mark N. Keene, C. M. Muirhead

Published Aug 1, 1988• 11 citations
Publisher

Abstract

The authors report measurements of the noise in a two-hole RF SQUID fabricated from YBCO by an erosion technique. The noise was measured from 10 mHz to 1 kHz. Above 25 Hz the noise is essentially white with an RMS value of 1.3*10 -3 phi 0 Hz -1/2 and is dominated by the noise of the amplifier. Below 1 Hz the noise power rises as 1/f 1.3 .

DOI
10.1088/0953-2048/1/2/002

Related papers

Noise measurements in a 2-hole radio frequency SQUID at liquid nitrogen temperature

S.P. Harrop, M. S. Colclough, Colin E Gough +2 more

The authors report measurements of the noise in a two-hole RF SQUID (superconducting quantum interference device) fabricated from bulk YBCO by an erosion technique in the frequency range 30 mHz to 1 kHz. Above 100 Hz the noise is essentially white with an RMS (root mean square) value of 5*10/sup -4/ phi /sub 0// square root Hz and is dominated by noise from the electronics. Below 10-Hz the noise power rises as 1/f/sup 0/9/.>

IEEE Transactions on Magnetics•Mar 1, 1989•2 citations

Noise in thin-film YBa2Cu3O7step-edge junction RF SQUIDS

J Sloggett, David L. Dart, C. P. Foley +3 more

We describe the noise performance of thin-film YBa 2 Cu 3 O 7 RF SQUIDS fabricated on MgO substrates with single step-edge Josephson junctions. A substantial range of noise levels has been observed for devices having similar electrical parameters (inductance, critical current, RF frequency). The best devices have white-noise levels below 10 -4 phi 0 Hz -1/2 when operated at a frequency of 170-200 MHz and have 1/f noise corners of a few hertz. Measurements of the V RF versus L RF characteristics of one SQUID, indicate that intrinsic device noise dominates the measured total noise of these devices. The white noise of all devices exceeds the predictions of the theory of Kurkijarvi at al. by a large factor, apparently because of non-ideal behaviour of step-edge Josephson junctions.

Superconductor Science and Technology•May 1, 1994•9 citations

Low-noise YBa2Cu3O7 rf SQUID magnetometer

Yi Zhang, H.-M. Mück, Klaus Dieter Herrmann +4 more

A superconducting quantum interferometer device (SQUID) electronics with tank frequencies near 150 MHz was constructed to enhance the rf SQUID sensitivity. By these means we characterized our YBa2Cu3O7 thin-film rf SQUIDs with step-edge junctions immersed in liquid N2. We obtained transfer function values of over 40 μV/Φ0, at a 50 Ω input impedance, for both hysteretic and dispersive mode of rf SQUID operation. The rms white and 1/f flux noise levels were significantly lower than at the tank frequency of 20 MHz. The best magnetic field sensitivity at 77 K was 0.9 pT/Hz1/2, and the energy resolution 1.4×10−28 J/Hz, down to 0.3 Hz.

Applied Physics Letters•Feb 3, 1992•81 citations

Characterization of the low-frequency noise in high-temperature radio frequency superconducting quantum interference devices cooled in static magnetic fields

J. Borgmann, P. David, Raphael Otto +2 more

We have performed a study of the low-frequency noise in high-temperature radio frequency (rf) superconducting quantum interference devices (SQUIDs) cooled in static magnetic fields. At 77 K, the noise of different thin-film YB2C3O7−x washer rf SQUIDs was measured in static magnetic fields up to 55 μT. The SQUID inductances ranged from 150 to 300 pH. The measured low-frequency flux noise of the SQUIDs SΦ1/2 at 1 Hz was between 70 and 350 μΦ0/√Hz, and in terms of magnetic field noise SB1/2 between 120 and 1100 fT/√Hz. The low-frequency noise of all devices at 1 Hz showed no significant increase for all applied static fields.

Applied Physics Letters•Feb 15, 1999•1 citation

Fabrication and performance of high T/sub c/ two hole bulk and single hole thick film RF SQUIDs at 77 K

Neeraj Khare, Anurag Gupta, Sangeeta Chaudhry +3 more

Two-hole YBCO bulk and one-hole YBCO, BSCCO thick-film RF SQUIDs have been fabricated and operated at 77 K. RF SQUID behavior has been studied using commercial RF SQUID electronics with external RF and AF sources. Flux noise density of these SQUIDs depends on the quality of the microbridge. Flux noise present in various reported high-T/sub c/ film RF SQUIDs is compared.

IEEE Transactions on Magnetics•Mar 1, 1991•5 citations

Low Frequency Noise Characteristic in HTS Step-Edge Junction Rf SQUID

S. K. H. Lam, Keith E. Leslie, Jeina Lazar

Rf SQUIDs have been fabricated on MgO substrate using step-edge YBCO junction. Ion beam etching as a post fabrication trimming process is routinely used to reduce (trim) the critical current of the junction for noise optimization. The white noise of SQUIDs with inductance,Ls= 157 pH can be reduced to 55μΦoHz−1/2after the trimming process. However, 1/f noise at low frequency has been found to be degraded after the trimming. Rf SQUIDs withLs= 130 pH were fabricated and measured. A similar noise performance was achieved in these SQUIDs down to 5 Hz without the need of trimming. The 1/f noise was found to be better than that of the trimmed SQUIDs.

IEEE Transactions on Applied Superconductivity•Mar 19, 2022•0 citations
The authors report measurements of the noise in a two-hole RF SQUID fabricated from YBCO by an erosion technique. The noise was measured from 10 mHz to 1 kHz. Above 25 Hz the noise is essentially white with an RMS value of 1.3*10 -3 phi 0 Hz -1/2 and is dominated by the noise of the amplifier. Below 1 Hz the noise power rises as 1/f 1.3 .
We describe the noise performance of thin-film YBa 2 Cu 3 O 7 RF SQUIDS fabricated on MgO substrates with single step-edge Josephson junctions. A substantial range of noise levels has been observed for devices having similar electrical parameters (inductance, critical current, RF frequency). The best devices have white-noise levels below 10 -4 phi 0 Hz -1/2 when operated at a frequency of 170-200 MHz and have 1/f noise corners of a few hertz. Measurements of the V RF versus L RF characteristics of one SQUID, indicate that intrinsic device noise dominates the measured total noise of these devices. The white noise of all devices exceeds the predictions of the theory of Kurkijarvi at al. by a large factor, apparently because of non-ideal behaviour of step-edge Josephson junctions.
A superconducting quantum interferometer device (SQUID) electronics with tank frequencies near 150 MHz was constructed to enhance the rf SQUID sensitivity. By these means we characterized our YBa2Cu3O7 thin-film rf SQUIDs with step-edge junctions immersed in liquid N2. We obtained transfer function values of over 40 μV/Φ0, at a 50 Ω input impedance, for both hysteretic and dispersive mode of rf SQUID operation. The rms white and 1/f flux noise levels were significantly lower than at the tank frequency of 20 MHz. The best magnetic field sensitivity at 77 K was 0.9 pT/Hz1/2, and the energy resolution 1.4×10−28 J/Hz, down to 0.3 Hz.
We have performed a study of the low-frequency noise in high-temperature radio frequency (rf) superconducting quantum interference devices (SQUIDs) cooled in static magnetic fields. At 77 K, the noise of different thin-film YB2C3O7−x washer rf SQUIDs was measured in static magnetic fields up to 55 μT. The SQUID inductances ranged from 150 to 300 pH. The measured low-frequency flux noise of the SQUIDs SΦ1/2 at 1 Hz was between 70 and 350 μΦ0/√Hz, and in terms of magnetic field noise SB1/2 between 120 and 1100 fT/√Hz. The low-frequency noise of all devices at 1 Hz showed no significant increase for all applied static fields.
Rf SQUIDs have been fabricated on MgO substrate using step-edge YBCO junction. Ion beam etching as a post fabrication trimming process is routinely used to reduce (trim) the critical current of the junction for noise optimization. The white noise of SQUIDs with inductance,Ls= 157 pH can be reduced to 55μΦoHz−1/2after the trimming process. However, 1/f noise at low frequency has been found to be degraded after the trimming. Rf SQUIDs withLs= 130 pH were fabricated and measured. A similar noise performance was achieved in these SQUIDs down to 5 Hz without the need of trimming. The 1/f noise was found to be better than that of the trimmed SQUIDs.