212 PART 2 QUANTUM MECHANICS AND SPECTROSCOPY
Computer:
Scan generation and
image display
(a)
Single-
tube
piezo
Electronics:
Positioning and feedback control
Signal conditioning
High voltage
piezo drive
Preamp
Tip bias
Current
collection
conversion
iv
Tunneling current
(b) Scan
Figure 10.12
A schematic
representation of (a)
a scanning tunneling
microscope with (b)
an expanded view of
the probe.