Insertable system for fast turnaround time microwave experiments in a dilution refrigerator

TL;DR

This paper introduces a rapid, insertable microwave measurement system for dilution refrigerators, reducing turnaround time from days to hours, enabling faster experiments in quantum research.

Contribution

The authors developed a cold-insertable probe system that significantly shortens measurement turnaround time in dilution refrigerators, facilitating more efficient quantum experiments.

Findings

Turnaround time reduced to 8 hours at 80 mK

System supports up to six transmission lines

Bandwidth tested up to 12 GHz, with potential for at least 18 GHz

Abstract

Microwave experiments in dilution refrigerators are a central tool in the field of superconducting quantum circuits and other research areas. This type of experiments relied so far on attaching a device to the mixing chamber of a dilution refrigerator. The minimum turnaround time in this case is a few days as required by cooling down and warming up the entire refrigerator. We developed a new approach, in which a suitable sample holder is attached to a cold-insertable probe and brought in contact with transmission lines permanently mounted inside the cryostat. The total turnaround time is 8 hours if the target temperature is 80 mK. The lowest attainable temperature is 30 mK. Our system can accommodate up to six transmission lines, with a measurement bandwidth tested between DC and 12 GHz. This bandwidth is limited by low pass components in the setup; we expect the intrinsic bandwidth to be at least 18 GHz. We present our setup, discuss the experimental procedure, and give examples of experiments enabled by this system. This new measurement method will have a major impact on systematic ultra-low temperature studies using microwave signals, including those requiring quantum coherence.