scholarly journals Strain and Spin-Orbit Coupling Engineering in Twisted WS2/Graphene Heterobilayer

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2921
Author(s):  
Cyrine Ernandes ◽  
Lama Khalil ◽  
Hugo Henck ◽  
Meng-Qiang Zhao ◽  
Julien Chaste ◽  
...  
Keyword(s):  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Twist Angle ◽  
Van Der Waals ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Electronic Band ◽  
Van Der Waals Materials

The strain in hybrid van der Waals heterostructures, made of two distinct two-dimensional van der Waals materials, offers an interesting handle on their corresponding electronic band structure. Such strain can be engineered by changing the relative crystallographic orientation between the constitutive monolayers, notably, the angular misorientation, also known as the “twist angle”. By combining angle-resolved photoemission spectroscopy with density functional theory calculations, we investigate here the band structure of the WS2/graphene heterobilayer for various twist angles. Despite the relatively weak coupling between WS2 and graphene, we demonstrate that the resulting strain quantitatively affects many electronic features of the WS2 monolayers, including the spin-orbit coupling strength. In particular, we show that the WS2 spin-orbit splitting of the valence band maximum at K can be tuned from 430 to 460 meV. Our findings open perspectives in controlling the band dispersion of van der Waals materials.

scholarly journals The effect of Rashba spin–orbit coupling on the spin- and valley-dependent electronic heat capacity of silicene

RSC Advances ◽  
2017 ◽  
Vol 7 (18) ◽  
pp. 10650-10659 ◽  
Author(s):  
Mohsen Yarmohammadi
Keyword(s):  
Heat Capacity ◽  
Band Structure ◽  
Electronic Band Structure ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Electronic Heat Capacity ◽  
Electronic Band ◽  
Rashba Spin ◽  
Electronic Heat

In this work, we have investigated the effect of an electric field and Rashba spin–orbit coupling on the electronic band structure and electronic heat capacity of a ferromagnetic silicene material in three phases at Dirac points.

FIRST-PRINCIPLES STUDIES ON THE ELECTRONIC STRUCTURE OF LuPd2Si2

2009 ◽  
Vol 23 (32) ◽  
pp. 5929-5934 ◽  
Author(s):  
T. JEONG
Keyword(s):  
Band Structure ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Spin Orbit Coupling ◽  
Electronic Band ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structure Scheme

The electronic band structure of LuPd 2 Si 2 was studied based on the density functional theory within local density approximation and fully relativistic schemes. The Lu 4f states are completely filled and have flat bands around -5.0 eV. The fully relativistic band structure scheme shows that spin–orbit coupling splits the 4f states into two manifolds, the 4f7/2 and the 4f5/2 multiplet.

scholarly journals Intriguing electronic, optical and photocatalytic performance of BSe, M2CO2 monolayers and BSe–M2CO2 (M = Ti, Zr, Hf) van der Waals heterostructures

RSC Advances ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 42-52
Author(s):  
M. Munawar ◽  
M. Idrees ◽  
Iftikhar Ahmad ◽  
H. U. Din ◽  
B. Amin
Keyword(s):  
Density Functional Theory ◽  
Band Structure ◽  
Density Functional ◽  
Photocatalytic Performance ◽  
Electronic Band Structure ◽  
Van Der Waals ◽  
Density Functional Theory Calculations ◽  
Van Der Waals Heterostructures ◽  
Electronic Band ◽  
Functional Theory

Using density functional theory calculations, we have investigated the electronic band structure, optical and photocatalytic response of BSe, M2CO2 (M = Ti, Zr, Hf) monolayers and their corresponding BSe–M2CO2 (M = Ti, Zr, Hf) van der Waals heterostructures.

Computational Prediction of New Series of Topological Ternary Compounds LaXS (X = Si, Ge, Sn) from First-Principles

J ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 577-588
Author(s):  
Jack Howard ◽  
Joshua Steier ◽  
Neel Haldolaarachchige ◽  
Kalani Hettiarachchilage
Keyword(s):  
Density Functional ◽  
Mechanical Stability ◽  
Computational Prediction ◽  
Orbit Coupling ◽  
Energy Calculation ◽  
Type I ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Electronic Band ◽  
The Stability

Dirac materials and their advanced physical properties are one of the most active fields of topological matter. In this paper, we present an ab initio study of electronics properties of newly designed LaXS (X = Si, Ge, Sn) tetragonal structured ternaries, with the absence and presence of spin–orbit coupling. We design the LaXS tetragonal non-symophic p4/nmm space group (no. 129) structures and identify their optimization lattice parameters. The electronic band structures display several Dirac crossings with the coexistence of both type I and type II Dirac points identified by considering the effect of spin–orbit coupling toward the linear crossing. Additionally, we perform the formation energy calculation through the density functional theory (DFT) to predict the stability of the structures and the elastic constants calculations to verify the Born mechanical stability criteria of the compounds.

Effects of Spin-Orbit Coupling on the Electronic and Excitonic Structures of Monolayer WS2

2019 ◽  
Vol 966 ◽  
pp. 48-53
Author(s):  
Budi Eka Dharma ◽  
Ahmad Syahroni ◽  
Muhammad Aziz Majidi
Keyword(s):  
Electronic Band Structure ◽  
Transition Metal Dichalcogenides ◽  
Grid Method ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Electronic Band ◽  
Independent Particle ◽  
Particle Level ◽  
Metal Dichalcogenides

Transition metal dichalcogenides (TMDs) display unique properties in their monolayer structures, namely a direct band-gap transition, which becomes a promising candidate for optoelectronics applications. Among them, WS2 exhibits strong spin-orbit interaction which splits the excitonic peaks as observed in the experimental data up to ~400 meV. Unlike the other TMDs, the first excitonic peak A is very sharp for WS2, while the secondary peak B is broader with smaller relative intensity. In this paper, we perform first-principles calculations on the electronic band structure and solve the Bethe-Salpeter equation for the complex dielectric function of monolayer WS2 to study the effects of spin-orbit coupling on its excitonic structures. To resolve the excitonic peaks, in particular the B peak, we implement the double-grid method. We discuss the effects of electron-hole interaction on the absorption spectrum by comparing it with that calculated at the independent-particle level.

scholarly journals Visualizing band structure hybridization and superlattice effects in twisted MoS2/WS2 heterobilayers

2D Materials ◽  
2021 ◽  
Author(s):  
Alfred J. H. Jones ◽  
Ryan Muzzio ◽  
Sahar Pakdel ◽  
Deepnarayanan Biswas ◽  
Davide Curcio ◽  
...  
Keyword(s):  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Twist Angle ◽  
Electronic States ◽  
Single Layer ◽  
Density Functional Theory Calculations ◽  
Layer Transition ◽  
Electronic Band ◽  
Wide Range

Abstract A mismatch of atomic registries between single-layer transition metal dichalcogenides (TMDs) in a two dimensional van der Waals heterostructure produces a moiré superlattice with a periodic potential, which can be fine-tuned by introducing a twist angle between the materials. This approach is promising both for controlling the interactions between the TMDs and for engineering their electronic band structures, yet direct observation of the changes to the electronic structure introduced with varying twist angle has so far been missing. Here, we probe heterobilayers comprised of single-layer MoS2 and WS2 with twist angles ranging from 2° to 20° and determine the twist angle-dependent evolution of the electronic band structure using micro-focused angle-resolved photoemission spectroscopy. We find strong interlayer hybridization between MoS2 and WS2 electronic states at the Γ-point of the Brillouin zone, leading to a shift of the valence band maximum in the heterostructure. Replicas of the hybridized states are observed at the centre of twist angle-dependent moiré mini Brillouin zones. We confirm that these replica features arise from the inherent moiré potential by comparing our experimental observations with density functional theory calculations of the superlattice dispersion. Our direct visualization of these features underscores the potential of using twisted heterobilayer semiconductors to engineer hybrid electronic states and superlattices that alter the electronic and optical properties of 2D heterostructures for a wide range of twist angles.

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