Related Experiment Video
Updated: Jun 24, 2025
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
9.6K
Coexistence of Interacting Charge Density Waves in a Layered Semiconductor
B Q Lv1,2,3,4, Alfred Zong2,5, Dong Wu6
1Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China.
Physical Review Letters
|June 3, 2024
Summary
Two interacting charge-density-wave (CDW) orders coexist in EuTe4. Time-resolved photoemission reveals distinct CDW behaviors and energy gaps in Te layers, driven by interlayer interactions.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Materials
Background:
- Coexisting orders are crucial in strongly correlated materials, driving phenomena like superconductivity and topological orders.
- EuTe4 exhibits anomalous thermal hysteresis and a semiconducting charge-density-wave (CDW) state without perfect Fermi surface nesting.
Purpose of the Study:
- To investigate the coexistence of two interacting charge-density-wave (CDW) orders in EuTe4.
- To understand the distinct behaviors and energy gaps of CDWs in Te monolayers and bilayers.
Main Methods:
- Time- and angle-resolved photoemission spectroscopy (TARPS) to probe unoccupied conduction bands.
- Analysis of energy gap evolution and renormalization dynamics post photoexcitation.
Main Results:
- Two distinct CDWs were identified in Te monolayers and bilayers, each with a unique energy gap.
- The CDW gaps showed dichotomous responses to photoexcitation; the bilayer gap renormalized less and recovered faster.
- The Te monolayer CDW exhibited momentum-dependent gap renormalization, not predicted by density-functional theory.
Conclusions:
- Interlayer interactions between the two CDW orders are responsible for the semiconducting ground state of EuTe4.
- These findings provide microscopic insights into EuTe4's correlated state and a nonequilibrium approach for studying complex layered systems.
More Related Videos
Related Concept Videos
01:21Carrier Transport
425
The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
425
01:24Metal-Semiconductor Junctions
334
The contact of metal and semiconductor can lead to the formation of a junction with either Schottky or Ohmic behavior.
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The...
334
01:12Fermi Level Dynamics
241
The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
241
01:28Standing Waves in a Cavity
905
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by:
905
02:32The de Broglie Wavelength
25.8K
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
25.8K
01:07Interference and Superposition of Waves
5.2K
When two waves of the same nature occur in the same region simultaneously, they result in interference. Interference of waves implies that the net effect of the waves is the sum of the individual waves' effects. However, it does not imply that the individual waves affect the propagation of other waves.
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
5.2K