Abstract
We present a numerical study of the influence of disorder on quantum-mechanical transmission by considering the presence of an impurity in a T-shaped quantum-wire junction. The device is modeled as an electron waveguide of finite cross section. Transmission and reflection probabilities are computed by use of a waveguide-matching technique. The calculations show that the transmission of the two-dimensional electron gas through the narrow-wide-narrow geometry can be both enhanced and suppressed by the presence of a repulsive impurity potential. Although perfect transparency is not generally achieved with the presence of a single impurity, we find a 100% modulation of conductance as one device parameter is changed, which is robust against the scattering. If the impurity is located in the narrow-wire region, a periodic oscillation appears in transmission due to multiple reflections between the impurity and the stub region. We also examine an attractive scatterer.
Original language | English (US) |
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Pages (from-to) | 6715-6720 |
Number of pages | 6 |
Journal | Physical Review B |
Volume | 45 |
Issue number | 12 |
DOIs | |
State | Published - 1992 |
ASJC Scopus subject areas
- Condensed Matter Physics