NanoSQUID-on-tip: Towards scanning magnetic microscopy with single spin sensitivity

TYPECondensed Matter Seminar
Speaker:Eli Zeldov
Location:Lidow Nathan Rosen (300)
Abstract:A scanning magnetic probe microscope based on a nanoSQUID residing on the apex
of a quartz tip has been developed. The nanoSQUID-on-tip device is fabricated by
pulling a quartz tube into a sharp pipette with diameters down to 50 nm followed by
deposition of a thin superconducting film onto the sides and the apex of the pipette. The
devices operate at 4 K in applied magnetic fields of up to 1 T and display an extremely
low flux noise of 50 nΦ_0/Hz^1/2
As a result, a record spin sensitivity of 0.4 μ_B/Hz^1/2
is achieved that is sufficient for detecting the magnetic moment of a single electron [1].
Using an AFM based technique the nanoSQUID can be scanned few nm above the
surface of the sample. The combination of high sensitivity, high spatial resolution, wide
bandwidth, and close proximity to the sample opens the pathway to direct imaging
and investigation of a wide range of static and dynamic magnetic phenomena on the
nanoscale. Preliminary results of study of vortex dynamics in superconductors will be

[1] D. Vasyukov, Y. Anahory, L. Embon, D. Halbertal, J. Cuppens, L. Neeman, A.
Finkler, Y. Segev, Y. Myasoedov, M. L. Rappaport, M. E. Huber, and E. Zeldov,
Nature Nanotech. 8, 639 (2013).