2004/03/03 by Ye Xiong, X. C. Xie, Xiong, Ye +3
Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #cond-mat.mes-hall
paper · pdf · doi:10.48550/arxiv.cond-mat/0403129
4 pages, 3 figures
arxiv created 2004/03/03 · arxiv updated 2009/12/01
We investigate the transmission of electrons through a quantum point contact by using a quasi-one-dimensional model with a local bound state below the band bottom. While the complete transmission in lower channels gives rise to plateaus of conductance at multiples of 2e2/h, the electrons in the lowest channel are scattered by the local bound state when it is singly occupied. This scattering produces a wide zero-transmittance (anti-resonance) for a singlet formed by tunneling and local electrons, and has no effect on triplets, leading to an exact 0.75(2e2/h) shoulder prior to the first 2e2/h plateau. Formation of a Kondo singlet from electrons in the Fermi sea screens the local moment and reduces the effects of anti-resonance, complementing the shoulder from 0.75 to 1 at low temperatures.