Related Experiment Video
Updated: Jan 12, 2026
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
10.2K
Supercurrent switch in π topological junctions based upon a narrow quantum spin Hall insulator.
Qingyun Yu1, Ze Tao2, Juntao Song3
1Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing, 210023, China.
Scientific Reports
|September 8, 2017
Summary
Interedge coupling in quantum spin Hall (QSH) insulators enables tunable Josephson π states. This transition, modulated by gate voltage, reveals helical spin textures and offers efficient supercurrent switching for advanced topological devices.
Area of Science:
- Condensed Matter Physics
- Topological Materials
- Quantum Phenomena
Background:
- Quantum spin Hall (QSH) insulators exhibit unique edge states crucial for topological superconducting devices.
- Interedge coupling in narrow QSH insulators can lead to exotic transport phenomena.
Purpose of the Study:
- Theoretically explore Josephson π states in QSH insulator strips coupled to s-wave superconductors.
- Investigate the impact of interedge coupling on Josephson junction properties.
Main Methods:
- Theoretical modeling of Josephson junctions in QSH insulator systems.
- Analysis of the influence of interedge coupling and gate voltage on the system's electronic states.
Main Results:
- Interedge coupling induces a gate-voltage-controlled 0–π transition in Josephson states.
- This transition is linked to interedge backscattering and reveals helical spin textures.
- A significant residual supercurrent at the transition point suggests efficient supercurrent switching.
Conclusions:
- The 0–π transition in QSH insulator Josephson junctions is a direct consequence of interedge coupling.
- These findings highlight the potential for QSH insulators in designing efficient supercurrent switches and precise π superconducting quantum interference devices.
Related Concept Videos
01:28Types Of Superconductors
1.6K
A superconductor is a substance that offers zero resistance to the electric current when it drops below a critical temperature. Zero resistance is not the only interesting phenomenon as materials reach their transition temperatures. A second effect is the exclusion of magnetic fields. This is known as the Meissner effect. A light, permanent magnet placed over a superconducting sample will levitate in a stable position above the superconductor. High-speed trains that levitate on strong...
1.6K
01:11P-N junction
1.1K
A p-n junction is formed when p-type and n-type semiconductor materials are joined together. At the interface of the p-n junction, holes from the p-side and electrons from the n-side begin to diffuse into the opposite sides due to the concentration gradient. This diffusion of carriers leads to a region around the junction where there are no free charge carriers, known as the depletion region. The charge density within the depletion region for the n-side and p-side can be described by the...
1.1K
01:27Biasing of Metal-Semiconductor Junctions
548
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...
548
01:24Superconductor
1.7K
A substance that reaches superconductivity, a state in which magnetic fields cannot penetrate, and there is no electrical resistance, is referred to as a superconductor. In 1911, Heike Kamerlingh Onnes of Leiden University, a Dutch physicist, observed a relation between the temperature and the resistance of the element mercury. The mercury sample was then cooled in liquid helium to study the linear dependence of resistance on temperature. It was observed that, as the temperature decreased, the...
1.7K
01:16Biasing of P-N Junction
1.8K
The operation of a p-n junction diode involves various biasing conditions, including forward bias, reverse bias, and equilibrium.
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
1.8K
01:24Metal-Semiconductor Junctions
893
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...
893