Quantum Measurement

The Fundamental Quantum Technologies (FQT) laboratory is located on level 3 of the Old Main Building at UNSW. It hosts state-of-the-art quantum measurement platforms for the operation of novel quantum devices at ultra-low temperatures, and a broad suite of electronic and microwave instruments.

The lab accommodates two BlueFors dilution refrigerators with several DC and AC lines (3x 50 GHz, 5x 18 GHz, 10x 80 MHz, 48x DC) for measuring quantum devices at temperatures of ~15 mK and magnetic fields of up to 7 T. The magnet has a 105 mm bore to accommodate large sample boards. Each setup uses three frames to decouple vibrations from the pumps, compressors and pulse tubes from the actual fridge. Pumps and compressors are located in a separate service corridor. The electronics in each measurement setup (DC voltage sources, arbitrary waveform generators, RF and MW sources, amplifiers, and digitizer) is connected a dedicated clean ground, separate from the building power.

Additionally to these two fridges, our group also uses a third BlueFors dilution refrigerator located in the Newton Building. This fridge has a vector magnet (5-1-1 T, 76 mm bore) to allow measurements in arbitrary magnetic field directions.

For quick-turnaround sample testing we have a number of dipsticks and variable temperature inserts (300 mK, 1K, 4.2 K), with and without magnetic fields of up to 4 T. Cold finger, high-frequency and low-triboelectric noise wiring, low-temperature filters, sample holders and high-frequency boards are designed and installed by our group.