Low-temperature scanning tunneling spectroscopy as a probe for a confined electron gas
M. Wenderoth; M. A. Rosentreter; K. J. Engel; A. J. Heinrich; M. A. Schneider; R. G. Ulbrich; M. Wenderoth; 4. Physikalisches Institut - Bunsenstraße 13, D-37073 Göttingen, Germany; M. A. Rosentreter; 4. Physikalisches Institut - Bunsenstraße 13, D-37073 Göttingen, Germany; K. J. Engel; 4. Physikalisches Institut - Bunsenstraße 13, D-37073 Göttingen, Germany; A. J. Heinrich; 4. Physikalisches Institut - Bunsenstraße 13, D-37073 Göttingen, Germany; M. A. Schneider; 4. Physikalisches Institut - Bunsenstraße 13, D-37073 Göttingen, Germany; R. G. Ulbrich; 4. Physikalisches Institut - Bunsenstraße 13, D-37073 Göttingen, Germany
Журнал:
EPL (Europhysics Letters)
Дата:
1999-03-01
Аннотация:
In situ cleaved (110) surfaces of n-doped GaAs have been investigated by scanning tunneling microscopy (STM) and spectroscopy (STS) at temperatures from 8 K to 300 K. At low temperatures oscillatory features in the topography around individual donor atoms embedded in the GaAs matrix and peaks in the differential conductivity (dI/dU) curves are seen. Both vanish with increasing temperature. The experimental results are described consistently in the framework of quantized subbands of a low-dimensional electron gas within the band-bending region which is induced by the STM tip. The quantization occurs at unpinned semiconductors surfaces and is also relevant for a quantitative understanding of STM data at room temperature.
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