Ningbo Materials has made important progress in the exploration of low-dimensional topological quantum materials

As a new quantum state of matter, topological state of matter includes topological insulators, topological semi-metals, and topological superconductors.
It has been one of the most attractive research hotspots in the field of condensed matter physics in the past ten years.
The belt structure has a topological structure in the inverted space, and its macroscopic physical properties such as electrical transport and thermal transport are all determined by the topological properties of the electron orbital wave function
.
This type of material has unique quantum properties.
Taking topological insulators as an example, it exhibits quantum phenomena and physical properties that are completely different from general insulators, such as topologically protected surface states, anti-weak localization, quantum spin/abnormal Hall Effect and so on
.
Because of the topological characteristics of topological insulators, it has broad application prospects in the fields of spintronics, low-power electronic devices, and quantum computers
.
Due to the protection of topological symmetry, the topological quantum number of topological materials is quite insensitive to local defects and disturbances, which provides an unparalleled innate advantage for the possible application of topological materials in quantum technology, and because of this, it is becoming more and more popular by researchers.
High attention and extensive research
.
Since the topological band theory was put forward, exploring new topological materials in the real world has become a very valuable work
.
? Since thermal fluctuation and quantum fluctuation effect increase significantly with the decrease of dimensionality, materials with low-dimensional structure often have many novel physical properties and application prospects
.
Most of the topological materials discovered in recent years have two-dimensional or three-dimensional structural characteristics, while topological materials with quasi-one-dimensional structures are relatively rare
.
Researcher He Shaolong of the Quantum Functional Materials Team of Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences recently discovered a new topological semi-metallic material TaPtTe5 in the study of the strange quantum properties of low-dimensional ternary tellurides
.
The research team carried out detailed measurement and analysis on the electrical transport, Hall and magnetoresistance of TaPtTe5, and studied the de Haas-van Alphen (dHvA) quantum oscillation of the material by low-temperature magnetic susceptibility measurement.
The quantum oscillation and data analysis results are shown in the figure.
As shown in 1, the two extracted oscillating frequencies correspond to the non-trivial Berry phase.
The first-principles band structure is shown in Figure 2.
The calculated topological index also confirms that it is a weak topological Dirac Semi-metallic materials, which are members of the research group following low-dimensional topological semi-metallic materials such as TaPdTe5 (Phys.
Rev.
B, 2020, 102, 075141) and TaNiTe5 (J.
Phys.
Chem.
Lett.
, 2020, 11, 1172) Later, another new topological material was discovered in this system.
Considering the layered low-dimensional structure and stability of this type of material, its discovery provides another ideal platform for the research and possible application of topological materials
.
? The dHvA quantum oscillations of TaPtTe5? The band structure of TaPtTe5? Recently this work was published in Phys.
Rev.
B, 2020, 103, 125 150 under the title of "Anisotropic transport and de Haas-van Alphen oscillations inquasi-one-dimensional TaPtTe5".
(DOI: 10.
1103/PhysRevB.
103.
125150)
.
This work was supported by the National Key Research and Development Program (2017YFA0303002), the National Natural Science Foundation of China (11674367, 11974364, U2032207, 11974061), and the Natural Science Foundation of Zhejiang Province (LY19A040002)
.