Computational Materials Function Research Unit

Principal Investigator

PI Name

Yong Xu

Degree

Ph.D.

Title

Unit Leader

Brief Resume

2010	Ph.D., Condensed Matter Physics, Tsinghua University, Beijing, China
2013	Alexander von Humboldt Fellow, Fritz Haber Institute, Berlin, Germany
2015	Research Scholar, Stanford University, USA
2015	Assistant Professor, Tsinghua University, Beijing, China
2015	Unit Leader, Computational Materials Function Research Unit, Cross-Divisional Materials Research Program, RIKEN Center for Emergent Matter Science (-present)
2018	Associate Professor, Tsinghua University, Beijing, China
2021	Professor, Tsinghua University, Beijing, China (-present)

Outline

We are a research group on theoretical and computational condensed-matter and materials physics. Our main research interest is to understand/predict unusual quantum phenomena and novel material properties, based on first-principles electronic structure calculations. In particular, we focus on exploring the electronic, thermal, optical and magnetic properties of low-dimensional systems (e.g. layered materials, materials surfaces and interfaces) as well as materials with non-trivial topological order. The primary goal of our research is to design advanced functional materials that can be used for low-dissipation electronics, high-performance thermoelectricity and high-efficiency solar cell. We are also interested in developing theoretical methods for studying quantum thermal, electronic, and thermoelectric transport at the mesoscopic scale.

Research Fields

Condensed Matter Physics, Materials Science

Keywords

First-principles calculations
Topological quantum matters
Thermoelectric effect
Thin films and interfaces
Theoretical materials design

Results

Discovery of graphene’s latest cousin: stanene

One of the grand challenges in condensed matter physics and material science is to develop room-temperature electron conduction without dissipation. Based on first-principles calculations, we predicted a new material class of stanene (i.e., the latest cousin of graphene) that is promising for the purpose. Stanene (from the Latin stannum meaning tin) is a 2D layer of tin atoms in a buckled honeycomb lattice. One intriguing feature of stanene and its derivatives is that the materials support large-gap quantum spin Hall (QSH) states, enabling conducting electricity without heat loss. Moreover, many other exotic characteristics were also proposed theoretically for stanene-related materials, including enhanced thermoelectric performance, topological superconductivity and the near-room-temperature quantum anomalous Hall effect. Very recently we have successfully fabricated the monolayer stanene structure by molecular beam epitaxy. This will stimulate great experimental effort to observe the unusual electronic properties of stanene.

(a) An element familiar as the coating for tin cans: tin (chemical symbol Sn).
(b) A 2D layer of tin, named stanene, when decorated by halogen atoms, is able to conduct electricity perfectly along its edges (blue and red arrows) at room temperature.
(c) The atomic structure model (top view) superimposed on the measured STM images for the 2D stanene on Bi₂Te₃(111).
(d) Side view.

Members

Yong Xu	Unit Leader

Publications

H. Li, Z. Wang, N. Zou, M. Ye, R. Xu, X. Gong, W. Duan, and Y. Xu

Deep Neural Network Representation of Density Functional Theory Hamiltonian

Nat. Comput. Sci. 2, 367 (2022)
Y. Li, J. Li, M. Ye, F. Zheng, Z. Zhang, J. Fu, W. Duan, and Y. Xu

High-Temperature Quantum Anomalous Hall Insulators in Lithium-Decorated Iron-Based Superconductor Materials

Phys. Rev. Lett. 125, 086401 (2020)
C. Liu, Y. Wang, H. Li, Y. Wu, Y. Li, J. Li, K. He, Y. Xu, J. Zhang, and Y. Wang

Robust axion insulator and Chern insulator phases in a two-dimensional antiferromagnetic topological insulator

Nat. Mater. 19, 522 (2020)
C. Wang, B. Lian, X. Guo, J. Mao, Z. Zhang, D. Zhang, B.-L. Gu, Y. Xu, and W. Duan

Type-II Ising Superconductivity in Two-Dimensional Materials with Spin-Orbit Coupling

Phys. Rev. Lett. 123, 126402 (2019)
J. Li, Y. Li, S. Du, Z. Wang, B.-L. Gu, S.-C. Zhang, K. He, W. Duan, and Y. Xu

Intrinsic magnetic topological insulators in van der Waals layered MnBi₂Te₄-family materials

Sci. Adv. 5, eaaw5685 (2019)