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Applied Physics A

, Volume 68, Issue 6, pp 637–641 | Cite as

Time-resolved current response of a nanosecond laser pulse illuminated STM tip

  • J. Jersch
  • F. Demming
  • I. Fedotov
  • K. Dickmann
Regular paper

Abstract.

Time-resolved dependence of the transient current through a ns laser pulse illuminated scanning tunneling microscope (STM) tip/sample gap in tunneling mode and out of tunneling range is presented. A self-designed fast STM-preamplifier (bandwidth 35 MHz) allows one to resolve the fine structure of the transient signal as well as the observation of some effects that are undetectable by using conventional low-band preamplifiers. The dependence of the threshold laser pulse intensity, which corresponds to the beginning of electron emission from tip (in non-tunneling mode), as a function of the tip/sample distance was investigated. At tip/sample distances from tunnel contact up to approximately 1 μm a linear dependence is found. This behavior is in good agreement with the theory for field enhancement in a STM tip/sample system. In tunneling mode a ns (fast component) as well as a μs (slow component) current response was found as a result of the laser pulse illumination. These data suggest the tip bending to be an important factor in clarifying the thermal/mechanical mechanism of laser-assisted surface nanomodification.

PACS: 61.16.P; 65.70; 79.20.Ds; 42.60.K 

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Copyright information

© Springer-Verlag 1999

Authors and Affiliations

  • J. Jersch
    • 1
  • F. Demming
    • 1
  • I. Fedotov
    • 1
  • K. Dickmann
    • 1
  1. 1.Lasercenter FH Muenster (LFM), FB Physikalische Technik, D-48565 Steinfurt, Germany (Fax: +49-2551/962-490, E-mail: laserlab@fh-muenster.de)DE

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