Construction of an ultra low temperature STM with a bottom loading mechanism

We have constructed and tested an ultra-low temperature scanning tunneling microscope that works with an atomic resolution at ultra low temperatures (T≥126 mK) in magnetic fields (B≤6 T) in ultra high vacuum (UHV). Clean sample surfaces can be prepared by several different methods and characterized by low energy electron diffraction in situ of UHV. A unique bottom loading mechanism enables us to cool back to the base temperature within 3 h after changing the sample and scanning tunneling microscopy tips