A multiloop SQUID and a SQUID array with 1-µm and submicrometer input coils

Research output: Contribution to journalArticleScientificpeer-review

7 Citations (Scopus)

Abstract

We have constructed a niobium multiloop SQUID current sensor and a 60-SQUID series array as a mix-and-match fabrication experiment utilizing our in-house projection stepper. The multiloop SQUID includes an input coil with a linewidth of 0.8 μm and a pitch of 1.6 μm, resulting in the mutual inductance M -1 = 1.8 μA/Φ 0 . The SQUID array is built on the same chip as the second-stage amplifier. The array and the multiloop showed white flux noise of 0.2 and 0.8 μΦ 0 Hz -1/2 at 4.2 K, respectively. Owing to the well-balanced gradiometric narrow-line construction, the two-SQUID system can be cooled down in the Earth's magnetic field and can be operated without superconducting or mu-metal shields. Excess low frequency noise was observed, whose possible origin in Josephson dynamics has been briefly studied with numerical simulation.
Original languageEnglish
Article number1600105
JournalIEEE Transactions on Applied Superconductivity
Volume22
Issue number4
DOIs
Publication statusPublished - 2012
MoE publication typeA1 Journal article-refereed

Fingerprint

SQUIDs
coils
inductance
niobium
Niobium
amplifiers
projection
chips
low frequencies
fabrication
Inductance
Linewidth
sensors
magnetic fields
metals
Metals
Earth (planet)
Magnetic fields
Fluxes
Fabrication

Keywords

  • Frequency-division multiplexing
  • magnetic resonance imaging (MRI)
  • magnetoencephalography (MEG)
  • SQUIDs

Cite this

@article{ce98e637249440e6a3b24ee161ff731b,
title = "A multiloop SQUID and a SQUID array with 1-µm and submicrometer input coils",
abstract = "We have constructed a niobium multiloop SQUID current sensor and a 60-SQUID series array as a mix-and-match fabrication experiment utilizing our in-house projection stepper. The multiloop SQUID includes an input coil with a linewidth of 0.8 μm and a pitch of 1.6 μm, resulting in the mutual inductance M -1 = 1.8 μA/Φ 0 . The SQUID array is built on the same chip as the second-stage amplifier. The array and the multiloop showed white flux noise of 0.2 and 0.8 μΦ 0 Hz -1/2 at 4.2 K, respectively. Owing to the well-balanced gradiometric narrow-line construction, the two-SQUID system can be cooled down in the Earth's magnetic field and can be operated without superconducting or mu-metal shields. Excess low frequency noise was observed, whose possible origin in Josephson dynamics has been briefly studied with numerical simulation.",
keywords = "Frequency-division multiplexing, magnetic resonance imaging (MRI), magnetoencephalography (MEG), SQUIDs",
author = "Mikko Kiviranta and Leif Gr{\"o}nberg and Juha Hassel",
note = "Project code: 19474",
year = "2012",
doi = "10.1109/TASC.2012.2190286",
language = "English",
volume = "22",
journal = "IEEE Transactions on Applied Superconductivity",
issn = "1051-8223",
publisher = "Institute of Electrical and Electronic Engineers IEEE",
number = "4",

}

A multiloop SQUID and a SQUID array with 1-µm and submicrometer input coils. / Kiviranta, Mikko; Grönberg, Leif; Hassel, Juha.

In: IEEE Transactions on Applied Superconductivity, Vol. 22, No. 4, 1600105, 2012.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - A multiloop SQUID and a SQUID array with 1-µm and submicrometer input coils

AU - Kiviranta, Mikko

AU - Grönberg, Leif

AU - Hassel, Juha

N1 - Project code: 19474

PY - 2012

Y1 - 2012

N2 - We have constructed a niobium multiloop SQUID current sensor and a 60-SQUID series array as a mix-and-match fabrication experiment utilizing our in-house projection stepper. The multiloop SQUID includes an input coil with a linewidth of 0.8 μm and a pitch of 1.6 μm, resulting in the mutual inductance M -1 = 1.8 μA/Φ 0 . The SQUID array is built on the same chip as the second-stage amplifier. The array and the multiloop showed white flux noise of 0.2 and 0.8 μΦ 0 Hz -1/2 at 4.2 K, respectively. Owing to the well-balanced gradiometric narrow-line construction, the two-SQUID system can be cooled down in the Earth's magnetic field and can be operated without superconducting or mu-metal shields. Excess low frequency noise was observed, whose possible origin in Josephson dynamics has been briefly studied with numerical simulation.

AB - We have constructed a niobium multiloop SQUID current sensor and a 60-SQUID series array as a mix-and-match fabrication experiment utilizing our in-house projection stepper. The multiloop SQUID includes an input coil with a linewidth of 0.8 μm and a pitch of 1.6 μm, resulting in the mutual inductance M -1 = 1.8 μA/Φ 0 . The SQUID array is built on the same chip as the second-stage amplifier. The array and the multiloop showed white flux noise of 0.2 and 0.8 μΦ 0 Hz -1/2 at 4.2 K, respectively. Owing to the well-balanced gradiometric narrow-line construction, the two-SQUID system can be cooled down in the Earth's magnetic field and can be operated without superconducting or mu-metal shields. Excess low frequency noise was observed, whose possible origin in Josephson dynamics has been briefly studied with numerical simulation.

KW - Frequency-division multiplexing

KW - magnetic resonance imaging (MRI)

KW - magnetoencephalography (MEG)

KW - SQUIDs

U2 - 10.1109/TASC.2012.2190286

DO - 10.1109/TASC.2012.2190286

M3 - Article

VL - 22

JO - IEEE Transactions on Applied Superconductivity

JF - IEEE Transactions on Applied Superconductivity

SN - 1051-8223

IS - 4

M1 - 1600105

ER -