#### Research Teams

**(1) Quantum Field Theory and Microscopic Structure of Matter **(Particle Physics, Particle Astrophysics & Nuclear Physics)

In the framework of quantum gauge field theory, the Standard Model of the strong, electromagnetic and weak interactions has enjoyed many splendid successes in the last decades, especially with the possible detection of its last predicted particle, the Higgs boson, very recently at LHC. Still, it suffers from some unsolved problems, such as: Why do particle masses and coupling constants have the values that we measure? Why are there three generations of particles? Why is there much more matter than antimatter in the universe? Where does dark matter fit into the model? Is it even a new particle? How to modify the classic Standard Model to include the neutrino mass? These problems suggest new physics beyond the Standard Model. On the other hand, within the Standard Model, it is still a challenge to understand and describe the formation and the forms of strongly interacting matter as hadrons and atomic nuclei due to its non-perturbative character of the underlying gauge theory, Quantum Chromodynamics (QCD) in the low energy regime. Aiming to solve these problems, the main research topics of this group currently include: models beyond the standard model including supersymmetry and grand unifications, Higgs phenomenology, dark matter models and detection, flavor mixing and CP violation, heavy flavor physics, neutrino physics, hadron structure and hadron spectroscopy, structure of exotic nuclei, structure and synthesis mechanism of superheavy nuclei, Lattice QCD, AdS/QCD and effective theories.

** (2) **String Theory, Gravity and Cosmology

Gravitation is one of four kinds of fundamental interactions in nature. As a theory of gravitation, the general relativity greatly succeeds in cosmology and astrophysics, and has been tested with great precision from the millimeter in small scale to the solar system in large scale. However, it is a fundamental problem whether the general relativity holds in other scales. The difficulty still exists as to unify the general relativity and quantum mechanics; to develop a theory of quantum gravity is one of most important challenges in modern theoretical physics. String theory is one of the most promising candidates of quantum gravity theory. On the other hand, with the development of modern high technology, cosmology enters into a precision era and “golden” time. All current observations indicates a concordance model: inflation⊕hot big bang⊕dark matter⊕dark energy. The research of this group currently focuses on topics in theory of quantum gravity and cosmology, including: the holographic principle of gravitation, black hole physics, thermodynamics of apparent horizon, entropic force formalism, Harava-Lifshitz gravity, applications of AdS/CFT correspondence in condensed matter physics, the nature of inflation, dark matter and dark energy, and CMB physics.

**(3) Statistical Physics and Theoretical Biophysics**

The research fields of this group cover a wide range in theoretical statistical mechanics, biophysics, chemical physics, bioinformatics, and their interdisciplinary applications. In recent years, scientific studies in this group concentrate on the following topics: 1) Bioinformatics, i.e., the application of statistical and linguistic methods in genomics and proteomics; 2) Statistical mechanics of molecular and cellular biological systems, such as single molecule biophysics of DNA, RNA, and proteins, elastic theory of bio-membranes, and self-assembly of nano and biomolecular systems; 3) Theoretical and experimental investigation of biological networks (gene regulation, cell-cycle control, etc.); 4) Statistical mechanics and physical properties of liquids and glassy systems; 5) Phase transitions and critical phenomena of complex and social networks; 6) Spin-glass theories for finite-connectivity systems and its application to information systems and hard combinatorial optimization problems. These studies help to understand how basic physics laws are transcribed into the rich diversity in nature. The distinct feature of our group is theoretical studies of biological, chemical, and complex systems from the perspective of statistical physics.

**(4) **Condensed Matter Physics and Quantum Physics

The research interests of this group cover a wide range of topics in condensed matter physics and quantum physics, such as the strongly correlated system, the topological states of matter, quantum information, quantum optical, atomic physics, and ultracold atomic gases. Specifically, we are interested in 1) physical mechanism of strongly correlated systems such as quantum Hall effect, high temperature superconductivity and giant magnetoresistance systems, quantum liquids and quantum critical phenomena; 2) development of the numerical simulation methods for the quantum many-body systems, including the density matrix renormalization group, the quantum Monte Carlo simulations, and the first principles and ab initio computational studies; 3) topological states of matter, e.g., the topological insulator and topological superconductor, non-abelian anyons and their application to topological quantum computation; 4) physical properties of mesoscopic systems, such as the coherence, correlation, fluctuation, dissipation, transports of the charge and spin of the current carriers, photons and neutral atoms; 5) the fundamental issues of quantum physics, such as quantum measurement and quantum decoherence/dissipation in quantum open systems; 6) quantum state engineering based on superconducting qubits and circuit quantum electrodynamics, and quantum phenomena in opto-mechanical systems; 7) exotic quantum phases in ultra-cold atomic and molecular gases, e.g., the dipolar Bose-Einstein condensates, degenerate Fermi gases with strong dipole-dipole interaction, and ultracold collisions of atoms and molecules; 8) coherent state transfer in quantum network, in particular, single photon transfer in coupled cavity array and the quantum transfer of collective excitations in a bio-network, such as photosynthesis and avian compass. The research topics also include developing the theoretical approach for the natural atoms and artificial systems in strong external fields, which is related to semi-classical physics and quantum chaos, and probing mathematical structures behind the dynamics of physical systems, such as quantum groups and Berry phase.