Lab Activities

Highlights of common tasks performed in the Coherent Spintronics research Group (CSG)

Probing devices at room temperature to test isolation or continuity. If devices exhibit desired electrical characteristics, they will be: mounted to PCB boards, wirebonded, tested at room temperature in a cryostat probe, and cooled for testing at cryogenic temperatures.

(Left) A crude example of how a potential Hall bar or quantum dot devices might be probed (Right) Magnified view of unfinished quantum dot device being probed.

Wirebond working devices are ready to cool down in liquid and dry cryostats to ~1.6K or tens of milli-Kelvin.

Example of a "tricky" CMOS device to wirebond due to the relatively small bond pad sizes i.e. ~40μm x 70μm.

From time to time, the liquid cryostat can accumulate frozen water/nitrogen/oxygen in undesired locations that impact the operation of the cryostat. This can require the cryostat to be warmed to room temperature to evaporate unwanted elements. This process is typically done in a manner that collects/recycles the precious Helium.

Liquid cryostat in process of being warmed up and evacuating previsouly frozen cryogenic liquides or water.