Connor Martin Holland
Postdoctoral Scholar, Physics
All Publications
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Determining the vibrations between sensor and sample in SQUID microscopy
APPLIED PHYSICS LETTERS
2016; 109 (23)
View details for DOI 10.1063/1.4971201
View details for Web of Science ID 000390677700030
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Scanning SQUID susceptometers with sub-micron spatial resolution
REVIEW OF SCIENTIFIC INSTRUMENTS
2016; 87 (9)
Abstract
Superconducting QUantum Interference Device (SQUID) microscopy has excellent magnetic field sensitivity, but suffers from modest spatial resolution when compared with other scanning probes. This spatial resolution is determined by both the size of the field sensitive area and the spacing between this area and the sample surface. In this paper we describe scanning SQUID susceptometers that achieve sub-micron spatial resolution while retaining a white noise floor flux sensitivity of ≈2μΦ0/Hz(1/2). This high spatial resolution is accomplished by deep sub-micron feature sizes, well shielded pickup loops fabricated using a planarized process, and a deep etch step that minimizes the spacing between the sample surface and the SQUID pickup loop. We describe the design, modeling, fabrication, and testing of these sensors. Although sub-micron spatial resolution has been achieved previously in scanning SQUID sensors, our sensors not only achieve high spatial resolution but also have integrated modulation coils for flux feedback, integrated field coils for susceptibility measurements, and batch processing. They are therefore a generally applicable tool for imaging sample magnetization, currents, and susceptibilities with higher spatial resolution than previous susceptometers.
View details for DOI 10.1063/1.4961982
View details for Web of Science ID 000385634500029
View details for PubMedID 27782557
https://orcid.org/0000-0003-1759-5912