Related Experiment Video
Updated: Jul 6, 2025
10:36
Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating
Published on: April 12, 2018
11.5K
Tunable valley polarization effect and second-order topological state in monolayer FeClSH
Mengteng Chen1, Xiangru Kong2, Xiao Xie1
1School of Science, Hebei University of Technology, Tianjin 300401, China. linyang.li@hebut.edu.cn.
Physical Chemistry Chemical Physics : PCCP
|January 10, 2024
Summary
Researchers discovered Janus FeClSH, a novel 2D material exhibiting spontaneous valley polarization (VP) without external fields. This ferrovalley material also shows potential for second-order topological insulator states, tunable via the Hubbard U parameter.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Breaking inversion symmetry in 2D materials is crucial for valleytronics.
- Ferrovalley (FV) materials offer spontaneous valley polarization (VP) due to magnetic exchange and spin-orbit coupling.
Purpose of the Study:
- To predict and investigate a new 2D material, Janus FeClSH, for its valleytronics and topological properties.
- To explore the potential of Janus FeClSH as a ferrovalley material and a second-order topological insulator (SOTI).
Main Methods:
- First-principles calculations were employed to study the electronic and topological properties of Janus FeClSH.
- Analysis included band structure, valley polarization, and topological state characterization.
Main Results:
- Janus FeClSH was predicted as a perfect FV material with spontaneous VP of 102.95 meV for out-of-plane magnetization.
- Circularly polarized light can induce VP for in-plane magnetization.
- Triangular nanoflakes of FeClSH exhibit nontrivial corner states, indicating a SOTI state.
Conclusions:
- Janus FeClSH is a promising 2D material for valleytronics and topological physics.
- The VP and SOTI properties are tunable with the Hubbard U parameter, enabling studies on their coupling.
More Related Videos
Related Concept Videos
01:27Biasing of Metal-Semiconductor Junctions
259
Biasing metal-semiconductor junctions involves applying a voltage across the junction. Specifically, the metal is connected to a voltage source, while the semiconductor is grounded. This technique is essential for controlling the direction and magnitude of current flow in electronic devices, including diodes, transistors, and photovoltaic cells.
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
259
01:27π Electron Effects on Chemical Shift: Overview
1.1K
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0,...
1.1K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
42.6K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
42.6K
02:58Crystal Field Theory - Octahedral Complexes
26.5K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
26.5K
02:37Metallic Solids
18.4K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
18.4K
01:18Fermi Level
604
The Fermi-Dirac function is represented by an S-shaped curve indicating the probability of an energy state being occupied by an electron at a given temperature. The Fermi level is the energy level at which there is a fifty percent chance of finding an electron, and it is positioned between the lower-energy valence band and the higher-energy conduction band.
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
604