Berlin 2005 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 22: Transport - Nanoelectronics II: Quantum Dots and Wires, Point Contacts
TT 22.13: Vortrag
Montag, 7. März 2005, 17:15–17:30, TU H2053
On the visibility of electron-electron interaction effects in field emission spectra of single-wall carbon nanotubes — •Thomas Schmidt and Andrei Komnik — Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
The electron-electron interaction effects turn out to alter considerably the energy-resolved current measured in field emission experiments. The most prominent feature is the so-called secondary current, which is related to the energy spectrum of the emitted electrons above the Fermi edge and which is brought about by processes of second order in tunnelling. The latter can be calculated exactly for a wide variety of emitters and turns out to be divergent towards EF. We perform an analysis of tunnelling processes of higher orders and show that they are divergent as well and overcome the leading order contributions sufficiently close to EF. Another effect which complicates the measurement of the secondary current is the thermal broadening of the Fermi edge. We discuss this aspect as well and make estimations for the energy and temperature windows for the secondary current to be reliably observable during field emission experiments from single-walled carbon nanotubes.