Sub-10 mK "In-cell" Magnetic Refrigeration for Cryogen-free Cryostats

TL;DR

This paper presents a novel 'in-cell' magnetic refrigeration technique enabling cryogen-free dilution refrigerators to reach sub-10 mK temperatures, with potential applications in low-dimensional quantum device research.

Contribution

The authors develop and demonstrate an 'in-cell' magnetic refrigeration method that achieves ultra-low temperatures below 5 mK in cryogen-free systems.

Findings

Achieved temperatures below 5 mK in cryogen-free dilution refrigerators.

Holding times at sub-5 mK range from 3 to 30 hours depending on magnetic field.

Technique enables study of low-dimensional devices at ultra low electron temperatures.

Abstract

A design and implementation of "in-cell" magnetic refrigeration to achieve sub-10 mK temperatures T in cryogen-free dilution refrigerators is presented. The ultra low temperatures below 5 mK are attained in finite magnetic fields B up to 1 T. The holding time below 5 mK varies between about 3 to 30 hours, depending on the final magnetic field after demagnetization process. The developed technique can be used to study low dimensional devices at ultra low electron temperatures in the High B/T regime.