Stability of topological properties of bismuth (1 1 1) bilayer.

J Phys Condens Matter

Department of Theoretical Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.

Published: April 2017

We investigate the electronic and transport properties of the bismuth (1 1 1) bilayer in the context of the stability of its topological properties against different perturbations. The effects of spin-orbit coupling variations, geometry relaxation and interaction with a substrate are considered. The transport properties are studied in the presence of Anderson disorder. Band structure calculations are performed within the multi-orbital tight-binding model and density functional theory methods. A band inversion process in the bismuth (1 1 1) infinite bilayer and an evolution of the edge state dispersion in ribbons as a function of spin-orbit coupling strength are analyzed. A significant change in the orbital composition of the conduction and valence bands is observed during a topological phase transition. The topological edge states are shown to be weakly affected by the effect of ribbon geometry relaxation. The interaction with a substrate is considered for narrow ribbons on top of another bismuth (1 1 1) bilayer. This corresponds to a weakly interacting case and the effect is similar to an external perpendicular electric field. Robust quantized conductance is observed when the Fermi energy lies within the energy gap, where only two counter-propagating edge states are present. For energies where the Fermi level crosses more in-gap states, scattering is possible between the channels lying close in the k-space. When the energy of the edge states overlaps the valence states, no topological protection is observed.

Download full-text PDF

Source
http://dx.doi.org/10.1088/1361-648X/aa5e79DOI Listing

Publication Analysis

Top Keywords

bismuth 1 1 1
16
1 1 1 bilayer
12
edge states
12
stability topological
8
topological properties
8
properties bismuth
8
transport properties
8
spin-orbit coupling
8
geometry relaxation
8
relaxation interaction
8

Similar Publications

In this work, the conventional melt quenching approach is used to synthesize the Pr doped NaF-BiO-BO-SiO (NBBS) glasses. The influence of Pr ions on their spectroscopic and structural characteristics in glass network is investigated. The amorphous nature of the samples has been amply verified by X-ray diffraction patterns.

View Article and Find Full Text PDF

High-Performance Bi-Based Catalysts for CO₂ Reduction: In Situ Formation of Bi/Bi₂O₂CO₃ and Enhanced Formate Production.

Adv Sci (Weinh)

January 2025

Advanced Materials and Catalysis Group, ZJU-Zhejiang Xinhua Low-Carbon Research Center, State Key Laboratory of Clean Energy Utilization, Institute of Catalysis, Department of Chemistry, Zhejiang University, Hangzhou, 310058, P. R. China.

The unavoidable self-reduction of Bismuth (Bi)-based catalysts to zero-valence Bi often results in detrimental adsorption of OCHO, leading to unsatisfactory selectivity of HCOOH in the electroreduction of carbon dioxide (CO). A novel Bi-tannin (Bi-TA) complex is developed, which undergoes in situ reconstruction into a Bi/Bi₂O₂CO₃ phase during CO reduction. This reconstructed catalyst exhibits high activity and selectivity, achieving a Faradaic Efficiency (FE) for formate production exceeding 90%, peaking at 96%.

View Article and Find Full Text PDF

pH-Triggered Phase Transitions, Coexposure of (001) and (110) Facets, and Oxygen Vacancies in BiOCl Photocatalysts.

Inorg Chem

January 2025

Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung, West Java 40132, Indonesia.

Bismuth oxychloride (BiOCl) is known for its unique layered microstructure, which plays a pivotal role in enhancing its photocatalytic properties. This study introduces a novel strategy for controlling the phase composition, facet orientation, and oxygen vacancy formation in BiOCl through precise pH adjustment during the synthesis. By employing a hydrothermal method, we systematically varied the pH to produce distinct BiOCl phases and conducted detailed structural and photocatalytic analyses.

View Article and Find Full Text PDF

Exposure to mid-energy radiation poses significant health risks, necessitating the development of effective shielding materials. Traditional lead-based shields, while effective, have significant drawbacks including toxicity and environmental concerns. This study investigates the potential of lead-free epoxy resin nanocomposites, incorporating bismuth oxide, nickel oxide, and cerium oxide, for mid-energy radiation protection.

View Article and Find Full Text PDF

Reactive oxygen species with evoked immunotherapy holds tremendous promise for cancer treatment but has limitations due to its dependence on exogenous excitation and/or endogenous HO and O. Here we report a versatile oxidizing pentavalent bismuth(V) nanoplatform (NaBiO-PEG) can generate reactive oxygen species in an excitation-free and HO- and O-independent manner. Upon exposure to the tumor microenvironment, NaBiO-PEG undergoes continuous H-accelerated hydrolysis with •OH and O generation through electron transfer-mediated Bi-to-Bi conversion and lattice oxygen transformation.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!