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We present a method to simulate ballistic quantum transport in one-dimensional nanostructures, such as extremely scaled transistors, with a channel of nanowires or nanoribbons. In contrast to most popular approaches, we develop our method employing an accurate plane-wave basis at the atomic scale while retaining the numerical efficiency of a localized (tight-binding) basis at larger scales. At the core of our method is a finite-element expansion, where the finite element basis is enriched by a set of Bloch waves at high-symmetry points in the Brillouin zone of the crystal. We demonstrate the accuracy and efficiency of our method with the self-consistent simulation of ballistic transport in graphene nanoribbon FETs.
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Pseudo-Spin Polarized One-Way Elastic Wave Eigenstates in One-Dimensional Phononic Superlattices
We investigate a one-dimensional discrete binary elastic superlattice bridging continuous models of superlattices that showcase a one-way propagation character, as well as the discrete elastic Su–Schrieffer–Heeger model, which does not exhibit this character. By considering Bloch wave solutions of the superlattice wave equation, we demonstrate conditions supporting elastic eigenmodes that do not satisfy the translational invariance of Bloch waves over the entire Brillouin zone, unless their amplitude vanishes for a certain wave number. These modes are characterized by a pseudo-spin and occur only on one side of the Brillouin zone for a given spin, leading to spin-selective one-way wave propagation. We demonstrate how these features result from the interplay of the translational invariance of Bloch waves, pseudo-spins, and a Fabry–Pérot resonance condition in the superlattice unit cell.
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- Award ID(s):
- 2242925
- PAR ID:
- 10520130
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Crystals
- Volume:
- 14
- Issue:
- 1
- ISSN:
- 2073-4352
- Page Range / eLocation ID:
- 1-13
- Subject(s) / Keyword(s):
- phononic superlattice pseudo spin one-way propagation topological acoustics
- Format(s):
- Medium: X Other: pdf
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/cryst14010092
