System of Tip Contacts with Micron Intercontact
                        Distance
                 M.V. Tsoi and  V.S. Tsoi
  Institute of Solid State Physics, Russian Academy of
         Sciences, 142432 Chernogolovka, Russia

     A technique for manufacturing and precise setting of
tip contacts at a small distances, down to the micron
level, is developed. The compactness of the device allows
one to place it inside a Dewar flask with liquid helium,
positioned between the poles of an electromagnet. The
technique was applied to the study of transverse electron
focusing under the conditions of small intercontact
distances, when the restrictions caused by a short mean
free path of electrons (holes) are lifted, and the
quantisation of electron orbits in the magnetic field
becomes significant.
Instruments and Experimental Technique, .39,  (1996)

              Transverse electron focusing
                        V.S. Tsoi
  Institute of Solid State Physics, Russian Academy of
         Sciences, 142432 Chernogolovka, Russia

     This brief article describes transverse electron
focusing applications for studying details of electron-
interface interaction, surface structure analysis,
quantum ballistics and the quantum Hall effect (QHE) in
Bi.
Physica B 218 , 1 (1996)

                 Drift electron focusing
                  M.V. Tsoi, V.S. Tsoi
  Institute of Solid State Physics, Russian Academy of
         Sciences, 142432 Chernogolovka, Russia

     A novel technique for studding the angular
dependence of the probability of conduction electron
specular reflection from a surface has been created by
means of drift transverse electron focusing. An angular
dependence was measured in Bi. We report observations of
quantum transverse electron focusing in Bi.
Physica B 218 ,14 (1996)

Transverse electron focusing, quantum electron kinetics,
                and the Hall effect in Bi
  V.S. Tsoi (*), M.D. Jaeger(**), B. Golding(**), M.V.
                  Tsoi(*), J. Bass(**)
(*)Institute of Solid State Physics, Russian Academy of
Sciences, 142432 Chernogolovka, Russia
(**) Physics&Astronomy Bldg., Michigan State University,
East Lansing, MI 48824-1116, USA

     A novel technique for studding electron kinetics has
been created by combining transverse electron focusing
(TEF) with microcontact resistance measurements.  The
technique provides a means to separate the contributions
of bulk and surface electron to magnetic field B
singularities. We report observations of a phenomenon
similar to the quantum Hall effect (QHE).
Physica B 218 ,22 (1996)

 Electronic  surface resonances in transverse-electron-
                  focusing experiments
V.S. Tsoi (*) (***), Y. de Wilde(*)(****), T. Noller(*),
A.G.M. Jansen(*), P.Wyder(*), D. Heitmann(**) and M. Riek
                          (**)
 (*)High Magnetic Field Laboratory, Max-Plank-Institut f
ìr Festkærperforschung and Centre National de la
Recherche Scientifique -B.P.166,f-38042 Grenoble Cedex,
France
(**)Max-Plank-Institute fìr Festkærperforschung -
Hersenbergstrasse 1, Stuttgart, Germany
(***) Institute of Solid State Physics, Russian Academy
of Sciences, 142432 Chernogolovka, Russia
(****)Also at: Universite Libre de Bruxelles, Service de
Physique des Solides, Boulevard du Triomphe, 1050
Bruxelles, Belgium

     The temporary trapping of conduction electrons in
surface states may result in singularities in the
scattering probability with respect to the incident
direction, so-called conduction electron surface
resonances, if the conservation of momentum can be
satisfied by a suitable surface structure. We present
evidence for the observation of these resonances by means
of transverse electron focusing on a Bi single crystal
with an artificially produced grating on the surface.
  Europhysics Letters, 35, 43 (1996)

   Lithographic point contacts for transverse electron
                   focusing in bismuth
    M.D. Jaeger(*), V. Tsoi(*)(**) and B. Golding(*),
(*)Department of Physics and Astronomy and Center for
Fundamental Materials Research, Michigan State
University, East Lansing, Michigan 48824-1116, USA
(**)Permanent address: Institute of Solid State Physics,
Russian Academy of Sciences, 142432 Chernogolovka, Russia

     An electron-beam lithography technique for
fabricating submicron point contacts to planar surfaces
of bulk samples is described. We have demonstrated the
technique by creating a linear array of point contacts,
oriented along the bisectrix axis of bismuth single
crystal, which act as emmiters and collectors in
multiprobe transport measurements. In a transverse
electron focusing geometry, we find the expected series
of periodic voltage peaks as a function of applied
magnetic field at low temperatures. The lithographically
fabricated contacts offer advantages over conducting-
needle probes in electrical integrity, thermal
robustness, lach of damage to the contact site, ability
to make multiple submicron contacts with <10 mm
separations and ability to align the contacts precisely
along crystallographic axes.
Appl.Phys.Lett., 68, 1282 (1996)