The Fano-Kondo Effect in Semiconductor Quantum Dots.

Autor: Katsumoto, Shingo, Sato, Masahiro, Aikawa, Hisashi, Iye, Yasuhiro
Předmět:
Zdroj: AIP Conference Proceedings; 2006, Vol. 850 Issue 1, p1361-1364, 4p, 1 Diagram, 5 Graphs
Abstrakt: We report observation of the Fano-Kondo effect in semiconductor quantum dot-wire hybrid systems. The Fano effect originates from the rapid change of phase shift by π at a quantum dot when the energy of incident electrons passes through a resonant point and results in distorsion in the spectrum of the transition probability. When it is combined with the Kondo effect, the lineshape of the conductance versus the gate voltage (i.e., the electron energy) reflects not only transmission probability but also the characteristic phase shift, e.g., locking to π/2 in the case of SU(2) Kondo effect. First in a quantum wire with a side-coupled quantum dot, clear Fano-Kondo effect with distortion parameter q = 0 has been observed. That is, the Kondo resonant transmission at Coulomb valleys has appeared as a revresed lineshape in the conductance, which verifies quantum coherence of the Kondo effect and at the same time, evidences phase shift locking to π/2. When an Aharonov-Bohm (AB) ring interferometer is adopted, the distortion parameter q can also be modified by the AB flux resulting in direct confirmation of the phase shift locking effect. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]
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