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Selected Applications
Premium Line - transport measurements
Piezo-Controlled Exfoliation of Graphene
In the group of Prof. Gosh at the IIS in Bangalore, researcher Kinikar
and his coworkers managed to measure the conductance of narrow
stripes of graphene during their exfoliation. A metal tip is crashed into
a graphite HOPG crystal using an attocube ANPz101 and slowly retract-
ed via a piezo tube. Conductance is measured from the tip through the
HOPG crystal. The setup situated inside a SEM is shown in picture 1. The
graphite piece sticking on the tip will thereby be torn to a single layer
of graphene. Mechanically torn graphene has highly crystalline edges,
leading to quantized conductance. This is due to one-dimensional
channels forming at the edges each with a conductance of 2e^2/h
(graph 2). A similar setup was used in a cryostat for high magnetic field
measurements (picture 3). Kinikar: “The attocubes have been with us
for over a decade, and they still work perfectly!”
A Kinikar, T P Sai, S Bhattacharyya, A Agarwala, T Biswas, S K Sarker, H R Krishnamurthy, M Jain, V B
Shenoy, A Ghosh ; Nature Nanotechnology 12, 564–568 (2017).
Mechanically Controlled Multi-Contact Break Junctions
In this application, small tips made from either glass or graphite were
used to locally deform a silicon membrane, creating break junctions in
a very controlled fashion. The tips with a typical radius between 50 and
200 microns were precisely controlled using attocube’s nanopositioning
technology. The approach of locally creating and controlling individual
break junctions can be used to study the influence of optical excitations
on the conductance of individual molecules and for controllable metallic
single-electron transistors.
Reprinted with permission from R. Waitz, O. Schecker and E. Scheer, Rev. Sci. Instrum. 79, 093901 (2008). © 2008,
American Institute of Physics.
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Piezo-based Nano Drives