Two-dimensional (2D) topological crystalline insulator, a new class where states are protected by lattice symmetry instead of by time-reversal symmetry, is predicted in PbSe monolayer based on first-principles electronic structure calculations. A combination of strong spin-orbit interaction with quantum confinement effects in PbSe monolayer lead to a topological phase transition with an even number of band inversion momentum space points. We demonstrate that the PbSe nanostructure presents pairs of spin-polarized Dirac cones coming from the monolayer edges, where each Dirac pair presents a unique spin alignment, leading to a quantum spin Hall system. More importantly, due to the quantum confinement this 2D nanostructure presents larger band gap as compared to its parent narrow band gap trivial insulator bulk PbSe, favoring a room-temperature 2D band gap with crystalline-protected Dirac states at the edges, turning this system interesting to combine nontrivial topological states with nanoelectronic and spintronic applications.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/nl502481f | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Realization of black phosphorus-like PbSe monolayer on Au(111) via epitaxial growth.
J Phys Condens Matter
September 2023
Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, People's Republic of China.
Lead selenide (PbSe) has been attracted a lot attention in fundamental research and industrial applications due to its excellent infrared optical and thermoelectric properties, toward reaching the two-dimensional limit. Herein, we realize the black phosphorus-like PbSe (-phase PbSe) monolayer on Au(111) via epitaxial growth, where a characteristic rectangular superlattice of 5 Å × 9 Å corresponding to 1 × 2 reconstruction with respect to the pristine of-phase PbSe is observed by scanning tunneling microscopy. Corresponding density functional theory calculation confirmed the reconstruction and revealed the driven mechanism, the coupling between monolayer PbSe and Au(111) substrate.
View Article and Find Full Text PDFReproduced out-of-plane ferroelectricity in monolayer SnTe van der Waals heterostructures.
J Phys Condens Matter
June 2023
Department of Physics, Xiangtan University, Xiangtan 411105, People's Republic of China.
Due to the shrinking in size of nonvolatile memory devices, the two-dimensional ferroelectric van der Waals (vdW) heterostructures have received huge attention. However, it is still difficult to maintain the out-of-plane (OOP) ferroelectricity. In this work, we have theoretically investigated the relationship between the ferroelectricity and the strain of bulk and few-layer SnTe by first-principles calculations.
View Article and Find Full Text PDFThe Adsorption Effect of Methane Gas Molecules on Monolayer PbSe with and without Vacancy Defects: A First-Principles Study.
Nanomaterials (Basel)
May 2023
Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronic, Xiangtan University, Xiangtan 411105, China.
In this paper, the adsorption effect of methane (CH) gas molecular on monolayer PbSe with and without vacancy defects is studied based on first-principles calculations. The effects of the adsorption of methane molecular on monolayer PbSe and on the Se vacancy (V) and Pb vacancy (V) of monolayer PbSe are also explored. Our results show that methane molecules exhibit a good physical adsorption effect on monolayer PbSe with and without vacancy defects.
View Article and Find Full Text PDFExtraordinary lattice thermal conductivity of gold sulfide monolayers.
Nanoscale Adv
June 2022
Department of Materials Science and Engineering, University of Toronto Toronto Ontario M5S 3E4 Canada
Gold sulfide monolayers (α-, β-AuS, α-, β-, γ-AuS) have emerged as a new class of two-dimensional (2D) materials with appealing properties such as high thermal and dynamical stability, oxidation resistance, and excellent electron mobility. However, their thermal properties are still unexplored. In this study, based on first-principles calculations and the Peierls-Boltzmann transport equation, we report the lattice thermal conductivity () and related phonon thermal properties of all members of this family.
View Article and Find Full Text PDFNanopore-Patterned CuSe Drives the Realization of the PbSe-CuSe Lateral Heterostructure.
ACS Appl Mater Interfaces
July 2022
Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, People's Republic of China.
Monolayer PbSe has been predicted to be a two-dimensional (2D) topological crystalline insulator (TCI) with crystalline symmetry-protected Dirac-cone-like edge states. Recently, few-layered epitaxial PbSe has been grown on the SrTiO substrate successfully, but the corresponding signature of the TCI was only observed for films not thinner than seven monolayers, largely due to interfacial strain. Here, we demonstrate a two-step method based on molecular beam epitaxy for the growth of the PbSe-CuSe lateral heterostructure on the Cu(111) substrate, in which we observe a nanopore-patterned CuSe layer that acts as the template for lateral epitaxial growth of PbSe.
View Article and Find Full Text PDFWant 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!