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Methods & Techniques

Low Noise Measurements

Transport Properties
Low-frequency Noise
Low Noise Measurements
Magnetic properties
SQUID Magnetometry
Torque Magnetometry
Thermodynamic properties
Specific Heat
Material Analysis
X-Ray Diffraction
Thin films & nanostructures
Thin Film Deposition
µK System
Dilution Refrigerators
ULT Thermometry
Bulk materials
Crystal Growth

DilUnitQubit For the electrical characterization of superconducting quantum circuits there are two 3He/4He dilution inserts and one 3He system available at the WMI. The dilution inserts are installed in rf-shielded rooms and three-fold mumetal shields are used to reduce rf-noise and magnetic field noise. One of the inserts is used for spectroscopic measurements and is equipped with a semirigid coaxial line, which is thermally anchored at 4 K and still temperature. The other set up is used for time domain measurements of the coherent quantum dynamics of superconducting qubits and is equipped with several coaxial lines which allow to apply microwave pulses with frequencies up to 20 GHz. In both dilution inserts special care was taken to ensure optimal filtering of all biasing lines. Here, several filtering systems at different temperatures (room temperature, 4.2 K, still and base temperature) are used to reduce perturbing rf-noise. For the pre-characterization of Josephson junctions, qubits and other circuit elements we have set up a 3He insert allowing measurements down to 300 mK with fast cool down and warm up times.

ProbingStation For the measurement of the S-parameters of superconducting microwave circuit elements (e.g. coplanar waveguide resonators, microwave beam splitters) we have set up a probing station allowing measurements down to below 4.2 K and frequencies up to 20 GHz. The probing station is equipped with 4 coplanar-to-SMA probing tips that can be positioned on the device under test and calibration structures using an optical microscope. This setup allows for a fast sample cool down and facilitates the measurement of a (large) number of samples during one and the same run.