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22 July 2021

New High-Magnetic-Field Thermometers for Sub-Millikelvin Temperatures

Drawing of observing the shape of the tuning fork resonance curve. Drawing of observing the shape of the tuning fork resonance curve. L. Steinke

This highlight focuses on the development of new thermometry required to study quantum materials and phenomena in high magnetic fields and at ultralow temperatures. The team has demonstrated that exceedingly small quartz tuning forks bathed in liquid 3He maintain a constant calibration that is magnetic field independent, thereby opening the use of these devices as new sensors of the response of quantum systems.

What did scientists discover?

The scientists demonstrated that new thermometers based on vibrating quartz tuning forks (the same devices used in quartz watches) – when bathed in liquid 3He - can be used for temperature measurements in extreme experimental environments, such as temperatures of order one millikelvin, even when combined with high magnetic fields.

THE TOOLS THEY USED

This research was conducted in the 16.5 Tesla Superconducting Magnet (Bay 3) at the High B/T Facility.

Why is this important?

Temperature measurements, which seem straightforward at room temperature, become extremely difficult near absolute zero. If the object being measured is a small crystal or microscopic device that is also subject to a high magnetic field, a typical scenario for many experiments at the MagLab, there are limited options for temperature measurements necessary to determine quantities like heat capacity or thermal conductivity. These measurements are fingerprints of the underlying quantum states in the material under study. This experimental work was conducted during the pandemic and involved a graduate student, a postdoctoral researcher, an undergraduate student, and an early career faculty scientist.

Who did the research?

Andrew J. Woods, Alexander M. Donald, Daniel M. Gitlin, Lucia Steinke

National MagLab and University of Florida

Why did they need the MagLab?

The MagLab High B/T facility is the only user facility worldwide that offers sub-millikelvin temperatures in combination with high fields up to 16 Tesla, the extreme environment for which this new thermometer technology is most needed.

Details for scientists

Funding

This research was funded by the following grants: G.S. Boebinger (NSF DMR-1644779); L. Steinke (MagLab User Collaboration Grant, 2021-2022)


For more information, contact Mark Meisel.

Details

  • Research Area: 2D,Condensed Matter Technique Development, Kondo/Heavy Fermion Systems, Quantum Fluids and Solids, Superconductivity - Basic
  • Research Initiatives: Materials
  • Facility / Program: High B/T
  • Year: 2021
Last modified on 22 July 2021