Unconventional Superconductors

(Zhu-an Xu, Hui-qiu Yuan, Guang-han Cao, Ming-hu Fang, Fan-long Ning etc)

Main research activities include exploring new unconventional superconductors and their mechanisms, and studying the quantum manipulation of correlated electronic systems. Currently we are interested in these unconventional superconductors: iron-based superconductors, heavy fermion superconductors, non-centrosymmetric superconductors, and topological superconductors.

In recent years, many outstanding achievements have been mades. For example, we discovered a new quasi one-dimensional chromium arsenide superconductor family K2Cr3As3 (A = K, Rb, Cs) and some other low-dimensional superconductors like Ta4Pd3Te16. We also designed and synthesized a variety of self-doping iron-based superconductors like Ba2Ti2Fe2As4O and KCa2Fe4As4F2. We made important contributions on the new kinds of iron selenium and nickel selenium superconductors, (Tl, K) Fe2Se2 and TlNi2Se2 etc., as well as new superconductors EuBiS2F and Eu3Bi2S4F4 associated with Eu mixed valence. We first observed the three-dimensional superconductivity of the two-dimensional layered iron-based superconductor, revealed the change of electronic states near the antiferromagnetic quantum critical point in CeTIn5 (T = Co, Rh, Ir) system, studied the relationship between non-centrosymmetric superconductivity and spin-orbit coupling, and proposed a new superconducting pairing state in CeCu2Si2. We were invited to write a review article for the journal of Reports on Progress in Physics. Meanwhile, we studied the novel quantum behavior of layered compound related to Iron-based superconductors, found several Kondo lattice systems and dilute magnetic semiconductors, and discovered an unconventional type of Kondo-destruction quantum phase transition.