A circuit for measuring the gap voltage of a scanning tunneling microscope on a nanosecond time scale
نویسندگان
چکیده
We demonstrate a new circuit design for fast measurements of the voltage drop across the gap of a scanning tunneling microscope ~STM! based on the simultaneous operation of two different amplifiers. The first is a fast instrumentation amplifier, sensing directly the voltage drop across the tunneling barrier, the second is a medium speed current amplifier with an overall gain of 10 V/A, suitable for normal STM operation. We obtained a time resolution of 10 ns measuring the plasma ignition under a STM tip during illumination with an intense 10 ns laser pulse. Possible applications include the study of STM point contacts. © 1999 American Institute of Physics. @S0034-6748~99!00504-3#
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