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Appendix B. Site Reports—Europe 169
Specific Project Highlights
Professor Dr. Ensslin, Professor of Physics at ETHZ, is also formally head of
the Paul Scherrer Institute Laboratory for Micro- and Nanostructures; a
position specifically designed to enhance close collaborations between the
two institutions. A long-time contributor to the study of functional
nanostructures, Professor Dr. Ensslin described some current projects
undertaken in his laboratory at ETHZ:
• Use of an atomic force microscope (AFM) to locally oxidize a structure,
forming a “quantum point contact” directly, without need for electronbeam
lithography or extensive alignment procedures. Professor Dr.
Ensslin noted the ease of use of commercially available AFMs and their
ready adaptability to lithography and materials modification at the
nanoscale (Held et al. 1997).
• Establishment of low temperature (1 K), high magnetic field (10 tesla)
capabilities to carry out scanning tunneling microscope (STM)
spectroscopy of semiconductor nanostructures in the quantum hall
regime.
• Wave function spectroscopy in specially tailored quantum wells grown at
the University of California in Santa Barbara.
The WTEC team also visited the laboratory of Dr. Hans von Känel, who
has developed an ultrahigh vacuum system for in situ growth and processing
of Si, Si/Ge materials that allow monitoring of the growth process; lowtemperature,
controlled materials modification; and STM analysis. The
system is also used for characterization of nanomechanical properties
through the ability to prepare and “load” (sputter-deposit materials)
cantilever probes in situ.
REFERENCES
Nanowissenschaften an der ETH Zürich. 18 May 1996.
Held, R., T. Heinzel, P. Studerus, K. Ensslin, and M. Holland. 1997. Fabrication of a
semiconductor quantum point contact by lithography with an atomic force microscope.
Applied Physics Letters Nov.