By means of magnetotransport measurements spin and quantum phenomena in semiconductor nanostructures can be investigated. Depending on the required measurement temperature different types of cryostats are used. In order to obtain high magnetic fields, often superconducting magnets are employed.
For extremely low temperatures an Oxford TLM 400 He-3/He-4 dilution refrigerator with a base temperature of 30 mK is available. This cryostat is equipped with a 14 T/16T magnet. In a dilution fridge a mixture of He-3 and He-4 is used for cooling. At low temperatures a phase separation into a He-3 rich and He-3 diluted phase occurs. The cooling power results from the transfer of He-3 from the He-3 rich into the He-3 diluted phase. Recently, a Leiden Cryogenics dilution refrigerator with a base temperature of 10 mK was installed. This system is equipped with a 12 T magnet and possesses a high frequency access.
For measurements down to 300 mK an Oxford He-3 cryostat is available, which is equipped with a 10 T magnet. For cooling down to base temperature previously condensed He-3 is pumped by a sorption pump.
In addition to the systems mentioned above it is also possible to measure samples in a He-4 continuous flow cryostat at temperatures from 4 K up to room temperature. Here, a magnetic field of 0.5 T can be applied.