Editor's note:
On June 24, the National Science and Technology Conference, the National Science and Technology Award Conference, and the Academician Conference of the Chinese Academy of Sciences and the Chinese Academy of Sciences were held in Beijing. Fang Zhong, a researcher from the Institute of Physics of the Chinese Academy of Sciences, won the first prize of the National Natural Science Award for his "Calculation and Prediction of Topological Electronic Materials". We invite the winning team to interpret the results.
Topological electronic states are a large new class of quantum states of matter
Its discovery and research have had a profound impact on the development of physics
It is an important scientific goal of current condensed matter physics research
In the study of topological electronic states
A range of typical topological electronic materials
It's all calculated and predicted first
And then there are experimental verifications
This not only expands the topological state classification
It has opened up new research directions
And it showed "compute-driven experiments."
The important role of this research paradigm
▲From left to right, the energy bands and chiral Weyl points of ordinary metals, Dirac semimetals, Weyl semimetals are distributed in the Fermi surface.
In 2010, the team passed the calculation
A material system and a specific scheme to realize the quantum anomalous Hall effect are proposed
Several experimental groups internationally have been based on this protocol
Precisely in the material system that is calculated and predicted
The quantum anomalous Hall effect was observed
The theoretical prophecy was confirmed
▲Cr or Fe doped Bi₂Se₃ topological insulator films can realize quantum anomalous Hall effect insulators
In 2012-2015, the team calculated the prediction and successfully discovered
The first Dirac semi-metal and the first Weyl semi-metal
This is the first time that this has been achieved in crystalline materials
"Chiral" electronic state – Weyl fermions
"Weylic fermions found in solids" results
Featured in the international journal Physical Review
Listed as one of the 49 most important works published in 125 years
It's the only job from China
▲The crystal structure and distribution of Weyl semi-metal TaAs were selected into the collection of the American Physical Society to commemorate the 125th anniversary of Physical Review
The results of this series led and promoted
In recent years, there has been a leap forward in the field of topological electronic state research
Proposed and realized
A universal calculation method for determining the topological properties of materials
▲Using the method of loop integration in differential geometry, a new graphical calculation scheme of topological numbers is obtained. a. The number of windings is equal to 0, indicating that the system topology is mediocre; b. The number of windings is equal to 1, indicating that the system topology is not mediocre.
This method avoids the difficulty of selecting the specification of the electron wave function
It is not limited by the symmetry of the material
It has become the main method for calculating and determining the topology category of materials
It is widely used by the international academic community
This has put the mainland at the forefront of the international research field
Editor in charge: Song Tongzhou