Effect of an impurity in a quantum resonator

Y. Takagaki, D. K. Ferry

Research output: Contribution to journalArticle

36 Scopus citations

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 languageEnglish (US)
Pages (from-to)6715-6720
Number of pages6
JournalPhysical Review B
Volume45
Issue number12
DOIs
StatePublished - Jan 1 1992

ASJC Scopus subject areas

  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Effect of an impurity in a quantum resonator'. Together they form a unique fingerprint.

  • Cite this