Measurement Setups
Dilution Refrigerator
We are equipped with two dilution refrigerators from the company BlueFors. Here we can apply high magnetic fields (~9T) while reaching down to 10 mK, temperatures necessary to measure effects like the quantum anomalous Hall effect or to establish quantum dots. Both fridges are equipped with measurement lines and amplifiers suitable for radio-frequencies. Low-noise cryogenic amplifiers, installed in one of the fridges, furthermore allows the conduction of noise measurements.
Cryogenic Probestation
To allow faster cooldowns than with the dilution fridges we upgraded the lab with a cryogenic probe station. Both suitable for DC as well as up to radio-frequency measurements it serves to do quick characterization measurements down to 5 K for many different materials and sample layouts. It is for example used to test superconducting devices, gate dielectrics and contact resistances.
Teslatron
Instruments
For experiments using radio-frequencies, specific equipment is necessary. We use for example:
- A fast arbitrary generator (Keysight M8196A) to address the devices with voltage pulses as short as <50 ps
- Lock-in amplifiers, low-noise amplifiers (from Low Noise Factory and CryoHEMT)
- Virtual Network Analyser ()
- Custom-made high-frequency sample holders (design: P. Pace, A. Denis and P. Morfin, ENS Paris)
Our noise measurement setup furthermore requires:
- Fast digitizers (from SP Devices and Spectrum Instrumentation)
- low-noise cryogenic amplifiers (Stahl electronics)
- superconducting coils ()
The lab is also equipped with Lock-in amplifiers (Zurich Instruments) and digital multimeters (Keithley) to conduct basic DC measurements and an atomic layer deposition (ALD) system, to pattern gate insulators and electrodes to tune the electron density in our devices.