Search of phase transitions using a helical cavity susceptometer

ORAL

Abstract

The synthesis of new quantum materials requires development of new experimental techniques for their characterization. Phase transitions (PT) convey “materials’ fingerprints”, however, a search of PTs implies complex and unique approaches, which are typically costly and time-demanding. We designed and built an inexpensive apparatus which enables detecting PTs of different types: normal-superconductor, metal-insulator, para-ferromagnet. The apparatus consists of a cylindrical helical cavity which is installed on a custom-made inset for a QD cryostat. A phase locked loop maintains a fundamental resonance mode at sub-GHz frequency, while the ambient temperature and magnetic field are varied (2-400 K, 0-90 kOe, respectively). It enables tracing the change in conductivity and magnetic permeability with very high sensitivity even in a 10-8 cc sample. We will demonstrate that device is extremely useful for studying PT phenomenon in low-dimensional magnetic heterostructures. Additionally, data for a few superconducting samples will be presented.

*This work was supported by the Office of Basic Energy Science, U.S. Department of Energy, BES-DMS funded by the Department of Energy’s Office of Basic Energy Science, DMR under grant DE FG02 87ER-45332.

–

Presenters

  • Pavel N. Lapa

    • University of California, San Diego

Authors

  • Pavel N. Lapa

    • University of California, San Diego

  • George Kassabian

    • University of California, San Diego

  • Nicolas M Vargas

    • Department of Physics, University of California, San Diego
    • University of California, San Diego
    • Department of Physics, University of California San Diego

  • Ivan Schuller

    • University of California, San Diego
    • Dept. of Physics and Center for Advanced Nanoscience, UCSD, La Jolla, CA, USA
    • Physics Department, University of California, San Diego
    • Department of Physics, University of California, San Diego