Watson 269A-B

Superconducting Quantum Circuits and Low Temperature Lab

We have recently installed in 269A-B a new cryogen-free (dry) BF-LD250 dilution refrigerator from Bluefors.  This dil fridge is capable of reaching 7mK base temperature, and is currently equipped with a series of optical fiber feed-thrus for low temperature optical measurements of devices, as well as x12 twisted pair lines (phosphor-bronze) for control/read-out of nanopositioning stages and x8 RF lines (SMA; 18GHz) for testing of microwave circuits and single-photon detector (SPD) read-out.  A set of attocube stages are mounted on the mixing chamber plate for nanopositioning of fiber-optics, and a pair of WSi SPDs provided to us by our JPL colleagues are located on the 800mK stage.  Currently two experiments co-habitate the BF-LD250 fridge, one involving optical measurements of silicon optomechanical crystals and the other involving electrical measurements of SiNx-membrane superconducting resonators coupled to nanomechanical resonators.