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

Mikko Kiviranta; Leif Grönberg; Juha Hassel

doi:10.1109/TASC.2012.2190286

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

Mikko Kiviranta, Leif Grönberg, Juha Hassel

Research output: Contribution to journal › Article › Scientific › peer-review

9 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 ₀Hz ^-1/2at 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 language	English
Article number	1600105
Journal	IEEE Transactions on Applied Superconductivity
Volume	22
Issue number	4
DOIs	https://doi.org/10.1109/TASC.2012.2190286
Publication status	Published - 2012
MoE publication type	A1 Journal article-refereed

Keywords

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

Access to Document

10.1109/TASC.2012.2190286

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 = "IEEE Institute of Electrical and Electronic Engineers",

number = "4",

}

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

SN - 1051-8223

VL - 22

JO - IEEE Transactions on Applied Superconductivity

JF - IEEE Transactions on Applied Superconductivity

IS - 4

M1 - 1600105

ER -

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

Abstract

Keywords

Access to Document

Fingerprint

Cite this