title: Atomic resolution scanning tunneling microscopy in a cryogen free dilution refrigerator at 15 mK.
abstract: Pulse tube refrigerators are becoming more common, because they are cost efficient and demand less handling than conventional (wet) refrigerators. However, a downside of a pulse tube system is the vibration level at the cold-head, which is in most designs several micrometers. We implemented vibration isolation techniques which significantly reduced vibration levels at the experiment. These optimizations were necessary for the vibration sensitive magnetic resonance force microscopy experiments at milli-kelvin temperatures for which the cryostat is intended. With these modifications we show atomic resolution scanning tunneling microscopy on graphite. This is promising for scanning probe microscopy applications at very low temperatures.
authors.affiliation: Department of Interface Physics, Leiden University, Niels Bohrweg 2, 2333CA Leiden, The Netherlands.
authors.forename: A M J
authors.initials: AM
authors.lastname: den Haan
authors.affiliation: Department of Interface Physics, Leiden University, Niels Bohrweg 2, 2333CA Leiden, The Netherlands.
authors.forename: G H C J
authors.initials: GH
authors.lastname: Wijts
authors.affiliation: Department of Interface Physics, Leiden University, Niels Bohrweg 2, 2333CA Leiden, The Netherlands.
authors.forename: F
authors.initials: F
authors.lastname: Galli
authors.affiliation: Leiden Cryogenics, Kenauweg 11, 2331BA Leiden, The Netherlands.
authors.forename: O
authors.initials: O
authors.lastname: Usenko
authors.affiliation: Leiden Spin Imaging (LSI), J.H. Oortweg 21, 2333CH Leiden, The Netherlands.
authors.forename: G J C
authors.initials: GJ
authors.lastname: van Baarle
authors.affiliation: Leiden Spin Imaging (LSI), J.H. Oortweg 21, 2333CH Leiden, The Netherlands.
authors.forename: D J
authors.initials: DJ
authors.lastname: van der Zalm
authors.affiliation: Department of Interface Physics, Leiden University, Niels Bohrweg 2, 2333CA Leiden, The Netherlands.
authors.forename: T H
authors.initials: TH
authors.lastname: Oosterkamp