A new Scanning Tunneling Microscope at magnetic fields of 22 T

A scanning tunneling microscope (STM) has been successfully installed in a dilution refrigerator with a 22T superconducting magnet. The set-up is mechanically isolated using a low vibration floating floor. We describe significant improvements in the thermalization and filtering of the wiring used in STM measurements, including a new high frequency filter and its characterization through ultra high resolution (8microeV) measurements in Al. We have successfully used the STM to measure single atom point contacts of gold, the vortex lattice in 2H-NbSe2 and have acquired atomic resolution images in 2H-NbSe2 above 20T. New results in several iron based superconductors will be also presented.