Construction of a versatile ultralow temperature scanning tunneling microscope.
We constructed a dilution-refrigerator (DR)-based ultralow temperature scanning tunneling microscope (ULT-STM) which works at temperatures down to 30 mK, in magnetic fields up to 6 T and in ultrahigh vacuum (UHV). Besides these extreme operation conditions, this STM has several unique features not available in other DR-based ULT-STMs. One can load STM tips as well as samples with clean surfaces prepared in an UHV environment to a STM head keeping low temperature and UHV conditions. After then, the system can be cooled back to near the base temperature within 3 h. Due to these capabilities, it has a variety of applications not only for cleavable materials but also for almost all conducting materials. The present ULT-STM has also an exceptionally high stability in the presence of magnetic field and even during field sweep. We describe details of its design, performance, and applications for low temperature physics.
Kambara
H
H
Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Matsui
T
T
Niimi
Y
Y
Fukuyama
Hiroshi
H
D004867:Equipment Design; D019544:Equipment Failure Analysis; D008280:Magnetics / Q000295:instrumentation*; D016252:Microscopy, Scanning Tunneling / Q000295:instrumentation* / Q000379:methods; D012034:Refrigeration / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000295:instrumentation* / Q000379:methods