On-chip SQUID measurements in the presence of high magnetic fields

TL;DR

This paper presents an on-chip SQUID measurement technique capable of operating in high magnetic fields up to 7 Tesla, enabling detailed studies of quantum tunneling in molecular magnets at low temperatures.

Contribution

The authors develop and detail a novel on-chip SQUID method for high-field magnetometry, allowing quantum tunneling observations in molecular magnets.

Findings

Observation of quantum tunneling jumps in Mn12-tBuAc

Calibration of SQUID measurements in high magnetic fields

Effect of transverse field on tunneling splitting

Abstract

We report a low temperature measurement technique and magnetization data of a quantum molecular spin, by implementing an on-chip SQUID technique. This technique enables the SQUID magnetometery in high magnetic fields, up to 7 Tesla. The main challenges and the calibration process are detailed. The measurement protocol is used to observe quantum tunneling jumps of the S=10 molecular magnet, Mn12-tBuAc. The effect of transverse field on the tunneling splitting for this molecular system is addressed as well.