Vibration measurements of a scanning SQUID microscope in a cryogen-free dilution refrigerator

ORAL

Abstract

Scanning probe microscopy is more challenging in cryogen-free systems due to vibrations introduced at the sample by the cryocooler. We built a cryogen-free scanning superconducting quantum interference device (SQUID) magnetic probe microscope operating in a cryogen-free dilution refrigerator with a base temperature of 10 mK. We report characterization of both the vibrations at the mixing chamber plate and of probe-to-sample vibrations. For the latter, we follow Schliessl et al. (Appl. Phys. Lett. 109, 232601 (2016)) and measure noise spectra at multiple locations above a sample where strong magnetic field gradients are present. This allows us to disentangle vibrations in different spatial directions. We find that the most pronounced vibrations are below 10 nm/Hz1/2 and occur at low harmonics of the pulse tube cycle. We will also discuss future improvements to our microscope and refrigerator that will further reduce the vibrations in our system.

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Presenters

  • David Low

    Laboratory of Atomic and Solid State Physics, Cornell University, Applied and Engineering Physics, Cornell University, Cornell University

Authors

  • David Low

    Laboratory of Atomic and Solid State Physics, Cornell University, Applied and Engineering Physics, Cornell University, Cornell University

  • George Ferguson

    Laboratory of Atomic and Solid State Physics, Cornell University, Cornell University

  • Alexander B Jarjour

    Cornell University

  • Rachel Resnick

    Cornell University

  • Brian Schaefer

    Cornell University

  • Eric N Smith

    Cornell University

  • Katja Nowack

    Laboratory of Atomic and Solid State Physics, Cornell University, Department of Physics, Cornell University, Cornell University