Related Experiment Video
Updated: Feb 13, 2026
07:14
Optogenetic Phase Transition of TDP-43 in Spinal Motor Neurons of Zebrafish Larvae
Published on: February 25, 2022
6.6K
Temperature-Induced Topological Phase Transition in HgTe Quantum Wells
A M Kadykov1,2, S S Krishtopenko1,2, B Jouault1
1Laboratoire Charles Coulomb, UMR 5221 Centre National de la Recherche Scientifique, University of Montpellier, F-34095 Montpellier, France.
Physical Review Letters
|March 16, 2018
Summary
Researchers directly observed a temperature-induced topological phase transition in HgTe quantum wells. They tracked Landau levels to pinpoint the critical temperature where the material shifts between trivial and topological insulator states.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Phenomena
Background:
- Topological insulators are materials with unique electronic properties, exhibiting an insulating bulk and conducting surface states.
- HgTe quantum wells are a key platform for studying topological phase transitions due to their tunable band structure.
Purpose of the Study:
- To directly observe and characterize the temperature-induced topological phase transition in HgTe quantum wells.
- To determine the critical temperature (Tc) at which the transition occurs.
Main Methods:
- Fabrication of a gated Hall bar device using HgTe quantum wells.
- Measurement and analysis of Landau levels using fan charts at varying temperatures.
- Tracking the temperature evolution of zero-mode Landau levels and their crossing point (Bc).
Main Results:
- Direct observation of Landau level splitting and crossing, indicative of an inverted band structure.
- Determination of the critical magnetic field (Bc) dependence on temperature.
- Extraction of the critical temperature (Tc) for the topological phase transition.
Conclusions:
- The study provides direct experimental evidence of a temperature-driven shift between trivial and topological insulator states in HgTe quantum wells.
- The vanishing of the bulk band gap at Tc signifies the transition, with a trivial gap observed above this temperature.
More Related Videos
Related Concept Videos
02:31Phase Transitions
23.3K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
23.3K
02:33Phase Transitions: Sublimation and Deposition
20.3K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
20.3K
02:39Phase Transitions: Melting and Freezing
15.3K
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
15.3K
02:39Phase Transitions: Vaporization and Condensation
21.6K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
21.6K
02:43Quantum Numbers
52.3K
It is said that the energy of an electron in an atom is quantized; that is, it can be equal only to certain specific values and can jump from one energy level to another but not transition smoothly or stay between these levels.
52.3K
02:39Phase Diagrams
50.4K
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
50.4K