Integrated Electronic Transport and Thermometry at milliKelvin Temperatures and in Strong Magnetic Fields

TL;DR

This paper presents a novel integrated system combining electronic transport measurements and real-time thermometry at millikelvin temperatures and high magnetic fields, using a He-3 immersion cell and quartz viscometry.

Contribution

The authors introduce a new field-independent thermometry scheme based on quartz tuning fork Helium-3 viscometry for ultra-low temperature measurements.

Findings

Temperature of 2D electron gas follows quartz viscometer down to 4mK

Successful operation of thermometry in strong magnetic fields

Integration of transport and thermometry at milliKelvin temperatures

Abstract

We fabricated a He-3 immersion cell for transport measurements of semiconductor nanostructures at ultra low temperatures and in strong magnetic fields. We have a new scheme of field-independent thermometry based on quartz tuning fork Helium-3 viscometry which monitors the local temperature of the sample's environment in real time. The operation and measurement circuitry of the quartz viscometer is described in detail. We provide evidence that the temperature of two-dimensional electron gas confined to a GaAs quantum well follows the temperature of the quartz viscometer down to 4mK.