Anomalous quantum scattering and transport of electrons with Mexican-hat dispersion induced by electrical potential

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Hauptverfasser: Yao, Jiating, Zhou, Benliang, Zhou, Xiaoying, Xiao, Xianbo, Zhou, Guanghui
Format: Preprint
Veröffentlicht: 2024
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author Yao, Jiating
Zhou, Benliang
Zhou, Xiaoying
Xiao, Xianbo
Zhou, Guanghui
author_facet Yao, Jiating
Zhou, Benliang
Zhou, Xiaoying
Xiao, Xianbo
Zhou, Guanghui
contents We theoretically study the quantum scattering and transport of electrons with Mexican-hat dispersion through both step and rectangular potential barriers by using the transfer matrix method. Owing to the torus-like iso-energy lines of the Mexican-hat dispersion, we observe the presence of double reflections and double transmissions in both two different barrier scenarios, i.e., the normal reflection (NR), retro-reflection (RR), normal transmission (NT), and specular transmission (ST).For the step potential with electrons incident from the large wavevector, the transmission is primarily governed by NT with nearly negligible ST, while the reflection is dominant by RR (NR) within (outside) the critical angle. Additionally, for electrons incident from the small wavevector, the NT can be reduced to zero by adjusting the barrier, resulting in a significant enhancement of ST and RR. For the rectangular barrier, the transmission and reflection spectra resemble those of the step barrier, but there are two kinds of resonant tunneling which can lead to perfect NT or ST. There exists a negative differential conductance (NDC) effect in the conductance spectrum. The conductance and the peak-to-valley ratio of the NDC effect can be effectively controlled by adjusting the height and width of the barrier as well as the incident energy. Our results provide a deeper understanding of the electron states governed by the Mexican-hat dispersion.
format Preprint
id arxiv_https___arxiv_org_abs_2403_09319
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Anomalous quantum scattering and transport of electrons with Mexican-hat dispersion induced by electrical potential
Yao, Jiating
Zhou, Benliang
Zhou, Xiaoying
Xiao, Xianbo
Zhou, Guanghui
Mesoscale and Nanoscale Physics
We theoretically study the quantum scattering and transport of electrons with Mexican-hat dispersion through both step and rectangular potential barriers by using the transfer matrix method. Owing to the torus-like iso-energy lines of the Mexican-hat dispersion, we observe the presence of double reflections and double transmissions in both two different barrier scenarios, i.e., the normal reflection (NR), retro-reflection (RR), normal transmission (NT), and specular transmission (ST).For the step potential with electrons incident from the large wavevector, the transmission is primarily governed by NT with nearly negligible ST, while the reflection is dominant by RR (NR) within (outside) the critical angle. Additionally, for electrons incident from the small wavevector, the NT can be reduced to zero by adjusting the barrier, resulting in a significant enhancement of ST and RR. For the rectangular barrier, the transmission and reflection spectra resemble those of the step barrier, but there are two kinds of resonant tunneling which can lead to perfect NT or ST. There exists a negative differential conductance (NDC) effect in the conductance spectrum. The conductance and the peak-to-valley ratio of the NDC effect can be effectively controlled by adjusting the height and width of the barrier as well as the incident energy. Our results provide a deeper understanding of the electron states governed by the Mexican-hat dispersion.
title Anomalous quantum scattering and transport of electrons with Mexican-hat dispersion induced by electrical potential
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2403.09319