IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Electronics Thursday Sessions
       Session EL-ThM

Paper EL-ThM8
Probing a One Dimensional Conductor Confined Below a Charged Step Edge

Thursday, November 1, 2001, 10:40 am, Room 124

Session: Quantum Electronics
Presenter: Chr. Meyer, Hamburg University, Germany
Authors: Chr. Meyer, Hamburg University, Germany
M. Morgenstern, Hamburg University, Germany
J. Klijn, Hamburg University, Germany
R. Wiesendanger, Hamburg University, Germany
Correspondent: Click to Email
Although one dimensional conductors exhibit unique properties, spatially resolved investigations are still rare. On InAs(110) we found a special type of charged step edge inducing a one dimensional electron system (1DES) below that step edge. We investigated this quantum wire with scanning tunneling spectroscopy (STS) over a length of 800 nm in various magnetic fields between 0 T and 6 T. The STS-curves on the step edge show two subbands of the 1DES with ground state energies of -66 meV for the first and -20 meV for the second subband giving an electron density of 1.2x10@super 8@/cm. Spatially resolved images of the local density of states (LDOS) reveal that the first and second subband have a width of 20 nm and 50 nm respectively. Along the step edge the LDOS of the 1DES shows an energy dependent fluctuation length in the range from 15 nm to 70 nm corresponding to the dispersion of InAs. We suggest that electron scattering on impurities in the quantum wire is responsible for the observed fluctuations in the LDOS. We compare our measurements with theoretical calculations of a random field disordered 1DES, that predict a broadening of the ideal 1D DOS.