Lanzhou University at present has formed a theoretical and experimental research team of particle physics focusing on hadron physics and heavy flavor physics. Members of the theoretical team include Prof. Zhang Zhaoxi (academician), Prof. Liu Xiang, Prof. Yu Fusheng, Associate Prof. Liu Zhanwei, Associate Prof. Sun Zhifeng, Dr. Li Feng (young researcher) and Dr. Luo Siqiang (postdoc station). The experimental team members include Dr. Wang Xiongfei (young researcher), Dr. Li Peirong (young researcher) and Dr. Xiao Dong (young researcher), who participated in the Beijing Spectrometer III (BESII) on the Beijing electron-positron collider (BEPC) in China. The particle physics research team of Lanzhou University is a vigorous research team and an important research team in China active in the frontier of hadron physics and heavy flavor physics. Our team has achieved a series of research results with important international impact:

1) The study of new hadron states is an important frontier in hadron physics, and is also an extremely competitive research field in the world. In recent years, our team has been tracking and paying attention to the latest research trends on new hadron states, and has also made in-depth research on various phenomenological models. The team systematically and deeply carried out fruitful phenomenological research on a series of new hadron states that found in major international high-energy physics experiments, and made a series of cutting-edge research achievements that attracted the attention of peers at home and abroad. Our research works have played a good theoretical guiding role in hadron physics research in major high-energy physics experiments in the world (BESII and BESIII experiment at BEPCII in China, BABAR experiment of SLAC National laboratory in the United States, Belle experiment of KEK laboratory in Japan, CDF experiment and DØ experiment of Fermilab in the United States, LHCb experiment and COMPASS experiment, etc.).

2）In 2009, Lanzhou University applied to join the BESIII Collaboration, which laid a foundation for the development of particle physics experiment of Lanzhou University. BESIII experiment aims for an experimental study of high-energy particle physics in τ- charm energy region using BESIII detector at BEPCII. In recent years, members of the high energy physics experiment of Lanzhou University who participates in BESIII experiment, have carried out systematic experimental research on the perturbative and non-perturbative problems in quantum chromodynamics around the international frontier research topics, such as the pair production and decay of strange hyperon pairs, the test of symmetry in strange hyperon decay, the accurate measurement of charm baryon branching ratio and the search for new strange hadron states. Many innovative experimental results have been achieved. These experimental results provide important experimental information and evidence for understanding and improving the theoretical models of hadron physics. Some of the experimental results have been widely cited by the international authoritative particle data group, and have become important experimental results in the field of hadron physics.

Our team is very active in academic exchanges. Team members have been invited to report their works at important academic conferences at home and abroad for many times. In addition, the team members also maintain close academic ties with their counterparts at home and abroad. The team initiated and held the "first joint symposium on the theory and experiment of hadron and heavy flavor physics" in 2018. So far, it has held two times, setting up an exchange platform for domestic peers engaged in the theoretical and experimental research of hadron and heavy flavor physics. The team recruits many postgraduates and doctoral students every year. Postdoctoral recruitment is open all year round. Visiting scholars at home and abroad are also welcome to visit.

Quantum technology has opened up a new revolutionary change of traditional sciences and technologies. As one of the pillars of quantum technology, quantum metrology explores the possibility of using quantum effects as resources, e.g., quantum entanglement and quantum squeezing, to surpass the restriction of classical measurement accuracy. It may provide a new breakthrough of existing techniques, such as time-frequency system, weak signal detection, radar imaging, and navigation position system, from the perspective of basic principles of quantum mechanics. However, the inevitable decoherence in quantum systems obstructs its practical realization and application. Therefore, how to understand and control decoherence effects on quantum metrology is the core problem in this field. On the other hand, Floquet engineering of quantum systems under periodic driving has become a versatile tool in quantum control. In particular, time crystal, a new type of nonequilibrium phase, produced by the Floquet engineering in recent years also provides a physical basis for us to explore the controlling effect of Floquet engineering on decoherence in quantum metrology.

By utilizing cold atoms and quantized optical field as quantum probes, we plan to investigate quantum gyroscope, quantum magnetometer, and quantum Radar. First, we will establish the explicit schemes to realize precisely detecting angular velocity and magnetic field, ranging distance, and imaging object.  Then, we will derive the physical condition to make the obtained precisions go beyond the shot noise limit. Lastly, we will explore the decoherence effects on these schemes and try to develop a universal decoherence suppression protocol based on Floquet engineering in quantum metrology.

Condensed matter physics is the science that deals with the macroscopic and microscopic physical properties of matter, which could include an extensive range of matter. Traditionally, understanding the fundamental principles of solids or fluids has been the most attractive subject in theoretical or experimental studies. Recently, more attentions are focused on the topological properties of insulators and emergent phenomena resulting from a large number of interacting particles. The history of the condensed-matter physics in Lanzhou University could be dated back to 1950s when Prof. Zheng Yang began studying the magnetism. After more than 60 years of development, different research areas of condensed-matter physics are conducted, including classical and quantum magnetism, strongly-correlated systems and high-T superconductivity and spintronics, as well as developing new algorithm for large scale numerical simulations. The most representative works include

(1)2004-2006, Luo et al., “Fano Resonance for Anderson Impurity Systems”, PRL;

Two PRB papers are highly cited;

(2)2008, Fang et al. “Kondo Effect in Carbon Nanotube Quantum Dots with Spin-Orbit Coupling”, PRL;

(3)2011, Oka, Tao et al., “Tuning tunneling magnetoresistance on the nanometer scale by spin-dependent quantum interference”, PRL;

(4)2013, Li et al., “The Kondo effect of an adatom in graphene and its scanning tunneling spectroscopy”, NJP (highlighted paper);

(5)2017, Ying, Luo et al., “Universal Scaling and Critical Exponents of the Anisotropic Quantum Rabi Model”, PRL (editor’s suggestion);

(6)2018, Jia et al., “Transformable ferroelectric control of dynamic magnetic permeability”, PRB(R);

   Zhong was selected as the distinguished reviewer of NJP.

(7)2019, Jia et al., “Twisted magnon beams carrying orbital angular momentum”, NC;

Statistical Physics and Complex Systems

Convener: Liang Huang

Institute of computational physics and complex systems (ICPCS) was founded in 2008 at Lanzhou university, with the director Prof. Lei Yang (adjunct) and three members Prof. Yinghai Wang, Lecs. Zigang Huang and Jianyue Guan.

In 2010, Prof. Liang Huang and Prof. Zhixi Wu successively joined, who set up stable research groups. In 2018, Prof. Zigang Huang left and Prof. Jing Yang joined, while Dr. Yisen Wang continued working as a postdoctoral fellow after graduation. In succeeding two years, Drs Mei Feng, Hongya Xu and Jiaqi Dong joined. Currently, there are eight members all together, and two main research directions/contexts of classical and quantum complex systems.

Research on nonlinearity and complexity — the coupling of structure, dynamics and function. It has been over three decades of history in the theoretical physics discipline of Lanzhou University. As far back as the mid-1980s, Prof. Yan Gu (now at University of Science and Technology of China) initiated studies in nonlinear dynamics at Lanzhou University, which lay a foundation for the nonlinear discipline establishment of Lanzhou University. Then in 1990s, Yang Gu, Yinghai Wang, Hong Zhao, Jiao Wang, Jie Yan, Liang Gao, Jing Cai et al. investigated symbolic dynamics and control of chaos in depth. Related studies were at the forefront of basic research (on nonlinearity and chaos) in China. Kongqing Yang, Yinghai Wang, Honggang Luo, Lei Yang, Zhengang Zhu, Xurong Chen, Yuren Shi, Weidong Zou, Hao Wang et al. did important works on the aspect of analytical solutions to nonlinear equations. In the year around 2000, Hong Zhao, Yong Chen, Lianchun Yu et al. conducted creative research on neural network dynamics. Meanwhile, Hong Zhao, Lei Yang, Haibin Li, Yong Zhang et al. did many international leading studies regarding the low-dimensional heat conduction problem. Since 2002, in-depth investigations on complex network structures, mutual dependence and coupling evolution of dynamics and function have been made by research groups (working on frontier topics in complexity science) with members Xinjian Xu, Zhixi Wu, Liang Huang, Zigang Huang, Jianyue Guan, Shengjun Wang et al. led by Yinghai Wang and Kongqing Yang, respectively. Current research contexts include propagation dynamics on complex structures, population expansion and cooperative evolution, computational neuroscience and brain disease, biophysics etc., where main researchers are Zhixi Wu, Jing Yang, Jianyue Guan, Lianchun Yu and Mei Feng.

Quantum complex systems: fundamental problems in the interdisciplinary field of quantum mechanics and statistical mechanics. Quantum chaos research in China dates back to the late 1980s, when Gongou Xu, Yan Gu and other older generation scholars did pioneering works (in the field). In the 90s of last century, Prof. Kongqing Yang working with Honggang Luo, Yan Luo, Xurong Chen, Qiang Gao, Fei Liu et al. made some investigations on the aspect of geometric quantization and its combination with nonlinear physics, and besides, with Mingqiu Luo, Mingyuan Wang, Xurong Chen et al., investigated wave phenomena in complex media and applied the research to geophysical prospecting. After returning to China in 2010, Prof. Huang set up the research group at Lanzhou University. A joint research center among Lanzhou University, Arizona State University and University of Aberdeen was founded in 2012. Team members actively participated in academic exchange activities with domestic and international leading experts, conducted international workshop on quantum chaos, and achieved a series of scientific research results. Current research contexts include relativistic quantum chaos, photonic crystal and quantum chaos, dynamics and micro-nano systems, classical and quantum thermalization, granular matter and basic problems in statistical physics, where main researchers are Liang Huang, Hongya Xu, Yisen Wang and Jiaqi Dong.