（1）主 题：Triboelectric nanogenerator based self-powered sensor for artificial intelligence
（2）主讲人： 崔鑫 物理学院博士后
In this talk, we briefly discuss capability and prospect of triboelectric nanogenerators being applied to intelligent sports, security, touch control, and document management systems. Triboelectric nanogenerator based sensor has excellent material compatibility, low cost, and flexibility, which is a unique candidate technology for artificial intelligence. Triboelectric nanogenerators effectively provide critical infrastructure for new generation of sensing systems that collect information by large amounts of self-powered sensors. The above fields have paid increasing attention in artificial intelligence technologies, such as machine learning, big data processing and cloud computing, demanding huge number of sensors and complicated sensors network.
Xin Cui is a post-doc majored in Physics. He received a Ph.D. in Chemical Engineering and Technology from Guangxi University under the supervision of Prof. Yan Zhang. His research interests include self-powered systems, artificial intelligence sensors, and dielectric capacitors for energy storage.
（1）主 题：Quantum anomaly in massive Dirac fermions
Helical symmetry of massive Dirac fermions is broken explicitly in the presence of electric and magnetic fields. Here we present two equations for the divergence of helical and axial vector currents following the Jackiw-Johnson approach to the anomaly of the neutral axial vector current. We discover the contribution from the helical symmetry breaking is attributed to the occupancy of the two states at the top of the valence band and the bottom of the conduction band. The explicit symmetry breaking fully cancels the anomalous correction from quantum fluctuation in the band gap. The chiral anomaly can be derived from the helical symmetry breaking. It provides an alternative route to understand the chiral anomaly from the point of view of the helical symmetry breaking. The pertinent physical consequences in condensed matter are the helical magnetic effect, which means a charge current circulating at the direction of the magnetic field, and the mass dependent positive longitudinal magnetoconductivity as a transport signature. The discovery not only reflects anomalous magnetotransport properties of massive Dirac materials, but also reveals the close relation between the helical symmetry breaking and the physics of chiral anomaly in quantum field theory and high energy physics.
Huanwen Wang currently works as a Postdoctoral Fellow in the School of Physics. He received the Bachelor degree from Beijing Normal University, MPhil degree from the Hong Kong University of Science and Technology, and PhD degree from the University of Hong Kong. Dr. Wang is working in the field of theoretical condensed matter physics. His research interests are mainly on the magnetotransport properties of topological materials, including the quantum anomaly effect in condensed matter systems, the magnetoelectric response of axion insulators, the mechanisms of negative magnetoresistance and so on.
（1）主 题：Electronic structure and hidden spin polarization effect in nonsymmorphic CeRh2As2
Since the recently discovered nonsymmorphic heavy fermion superconductor CeRh2As2 contains rich physical properties and has a similar structure to Bi2212, some works have been performed on the relationship between special crystal structure and superconductivity and transport properties. However, the accurate electronic structure of CeRh2As2 and whether there is a hidden spin polarization (HSP) effect have not been experimentally reported so far. In view of this, We are going to perform the following research: i) comprehensively and accurately study the electronic structure of CeRh2As2 by angle-resolved photoemission spectroscopy (ARPES); ii) Systematically explore whether there is a non-trivial spin-momentum-layer locking phenomenon in CeRh2As2 (i.e., the HSP effect) by spin ARPES; iii) Study the relationship between SOC and superconductivity and topology in CeRh2As2, as well as explore whether CeRh2As2 has an undiscovered quantum phase at low temperatures. The successful implementation of this research can not only solve the urgent experimental need for the electronic structure of CeRh2As2, but also construct a research paradigm for HSP effect in multiphase heavy fermion superconductors， meanwhile, it can also provide new experimental evidences for exploring nontrivial topological phenomenon of strongly correlated electron.
Ke Zhang is a post-doc majored in Physics. He obtained bachelor’s degree in Materials Science and Engineering in Central South University, and PhD degree in condensed matter physics from Hiroshima University under the supervision of Prof. Kenya Shimada. His research interests mainly focus on the world-leading high-resolution spin and angle-resolved photoemission spectroscopy (ARPES) of correlated and topological materials using ultraviolet and vacuum ultraviolet synchrotron radiation. He has published many peer-reviewed research papers and coauthor papers, including Phys. Rev. X, Phys. Rev. Lett., Phys. Rev. B, Adv. Mater., Renew. Sust. Energ. Rev., Sol. Energy, ACS Appl. Mater. Interfaces, Surf. Coat. Technol., Vacuum etc.
编辑：林坤 / 审核：林坤 / 发布：陈伟