TY - JOUR
T1 - Observation of signatures of subresolution defects in two-dimensional superconductors with a scanning SQUID
AU - Noad, Hilary
AU - Watson, Christopher A.
AU - Inoue, Hisashi
AU - Kim, Minu
AU - Sato, Hiroki K.
AU - Bell, Christopher
AU - Hwang, Harold Y.
AU - Kirtley, John R.
AU - Moler, Kathryn A.
N1 - Funding Information:
This work was supported by the Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, under Contract No. DE-AC02-76SF00515. H.N. acknowledges support from a Stanford Graduate Fellowship and a Natural Sciences and Engineering Research Council of Canada PGS M and PGS D. We would like to thank M. Hosoda for assistance with sample fabrication and V. Kogan for useful discussions. We acknowledge E. Track, M. Stoutimore, and V. Talanov of Northrop Grumman Mission Systems for fruitful discussions and for providing samples for this work.
Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/8/21
Y1 - 2018/8/21
N2 - The diamagnetic susceptibility of a superconductor is directly related to its superfluid density. Mutual inductance is a highly sensitive method for characterizing thin films, however, in traditional mutual inductance measurements, the measured response is a nontrivial average over the area of the mutual inductance coils, which are typically of millimeter size. Here we measure localized, isolated features in the diamagnetic susceptibility of Nb superconducting thin films with lithographically defined through holes, δ-doped SrTiO3, and the two-dimensional electron system at the interface between LaAlO3 and SrTiO3, using scanning superconducting quantum interference device susceptometry, with spatial resolution as fine as 0.7μm. We show that these features can be modeled as locally suppressed superfluid density, with a single parameter that characterizes the strength of each feature. This method provides a systematic means of finding and quantifying submicron defects in two-dimensional superconductors.
AB - The diamagnetic susceptibility of a superconductor is directly related to its superfluid density. Mutual inductance is a highly sensitive method for characterizing thin films, however, in traditional mutual inductance measurements, the measured response is a nontrivial average over the area of the mutual inductance coils, which are typically of millimeter size. Here we measure localized, isolated features in the diamagnetic susceptibility of Nb superconducting thin films with lithographically defined through holes, δ-doped SrTiO3, and the two-dimensional electron system at the interface between LaAlO3 and SrTiO3, using scanning superconducting quantum interference device susceptometry, with spatial resolution as fine as 0.7μm. We show that these features can be modeled as locally suppressed superfluid density, with a single parameter that characterizes the strength of each feature. This method provides a systematic means of finding and quantifying submicron defects in two-dimensional superconductors.
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U2 - 10.1103/PhysRevB.98.064510
DO - 10.1103/PhysRevB.98.064510
M3 - Article
AN - SCOPUS:85052828555
VL - 98
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 6
M1 - 064510
ER -