Reducing current noise in cryogenic experiments by vacuum-insulated cables

TL;DR

This paper demonstrates that vacuum-insulated cables significantly reduce current noise in cryogenic experiments, achieving low noise levels across a broad frequency range, which enhances measurement precision in cryogenic setups.

Contribution

It introduces the use of vacuum-insulated cables to suppress vibration-induced current noise in cryogenic experiments, providing a practical noise reduction method.

Findings

Vibration-induced noise is effectively suppressed by vacuum-insulated cables.

Achieved a noise peak below 4 fA at 1.4 Hz.

Obtained a white noise density of 0.44 fA/√Hz in the millihertz range.

Abstract

We measure the current noise of several cryogenic cables in a pulse tube based dilution refrigerator at frequencies between about 1~mHz and 50~kHz. We show that vibration-induced noise can be efficiently suppressed by using vacuum-insulated cables between room temperature and the 2nd pulse tube stage. A noise peak below 4 fA at the 1.4~Hz operation frequency of the pulse tube, and a white noise density of 0.44 fA/\sqrt{Hz} in the millihertz range are obtained.