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Conductance Quantization in a Periodically Modulated Quantum Channel: backscattering and mode mixing

P. Singha Deo·B. C. Gupta·A. M. Jayannavar·F. M. Peeters
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Abstract

It is known that the conductance of a quantum point contact is quantized in units of $2e^2/h$ and this quantization is destroyed by a non-adiabatic scatterer in the point contact, due to backscattering. Recently, it was shown [Phys. Rev. Lett. 71, 137 (1993)] that taking many non-adiabatic scatterers periodically in a quantum channel, the quantization can be recovered. We study this conductance quantization of a periodic system in the presence of a strong defect. A periodic arrangement of double-stubs give remarkable quantization of conductance. A periodic arrangement of double-constrictions also gives a very good quantization only when the separation between the constrictions is small. We conclude that conductance quantization of a periodically modulated channel is robust.

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P. Singha Deo, B. C. Gupta, A. M. Jayannavar, F. M. Peeters. 1997-09-25. Conductance Quantization in a Periodically Modulated Quantum Channel: backscattering and mode mixing. https://arxiv.org/abs/cond-mat/9709276

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