Application of SQUIDs to low temperature and high magnetic field measurements - Ultra low noise torque magnetometry

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • F. Arnold - , Max Planck Institute for Chemical Physics of Solids (Author)
  • M. Naumann - , Max Planck Institute for Chemical Physics of Solids, Technical University of Munich (Author)
  • Th Lühmann - , Max Planck Institute for Chemical Physics of Solids (Author)
  • A. P. Mackenzie - , Max Planck Institute for Chemical Physics of Solids, University of St Andrews (Author)
  • E. Hassinger - , Max Planck Institute for Chemical Physics of Solids, Technical University of Munich (Author)

Abstract

Torque magnetometry is a key method to measure the magnetic anisotropy and quantum oscillations in metals. In order to resolve quantum oscillations in sub-millimeter sized samples, piezo-electric micro-cantilevers were introduced. In the case of strongly correlated metals with large Fermi surfaces and high cyclotron masses, magnetic torque resolving powers in excess of 104 are required at temperatures well below 1 K and magnetic fields beyond 10 T. Here, we present a new broadband read-out scheme for piezo-electric micro-cantilevers via Wheatstone-type resistance measurements in magnetic fields up to 15 T and temperatures down to 200 mK. By using a two-stage superconducting-quantum interference device as a null detector of a cold Wheatstone bridge, we were able to achieve a magnetic moment resolution of Δm = 4 × 10-15 J/T at maximal field and 700 mK, outperforming conventional magnetometers by at least one order of magnitude in this temperature and magnetic field range. Exemplary de Haas-van Alphen measurement of a newly grown delafossite, PdRhO2, was used to show the superior performance of our setup.

Details

Original languageEnglish
Article number023901
JournalReview of scientific instruments
Volume89
Issue number2
Publication statusPublished - 1 Feb 2018
Peer-reviewedYes
Externally publishedYes

External IDs

PubMed 29495810

Keywords