An ultralow-temperature scanning tunnelling microscope

We have developed a home-built ultralow-temperature scanning tunnelling microscope (STM) capable of continuous operation down to 70 mK, and in a magnetic field of up to 12 T. Extensive testing has shown that the STM is capable of very stable operation, including atomic resolution and spectroscopy with a high energy resolution. To test the microscope we have investigated the structural and electronic properties of the type-II superconductor NbSe2.