Multipolar nematic state of nonmagnetic FeSe based on DFT plus U

Article

关键词: SUPERCONDUCTIVITY;    FRUSTRATION;    MAGNETISM;   

DOI  :  10.1103/PhysRevB.104.L161110

来源: SCIE

【 摘 要 】

Clarifying the origin of nematic state in FeSe is one of urgent problems in the field of iron-based superconductivity. Motivated by the discovery of a nematic solution in the density-functional theory implemented by on-site Coulomb interaction (DFT+U) [npj Quantum Mater. 5, 50 (2020)], we reexamine the U dependence of electronic states in the nonmagnetic normal state of FeSe and perform full multipolar analyses for the nematic state. We find that with increasing U the normal state experiences a topological change in the Fermi surfaces before the emergence of a nematic ground state. The resulting nematic ground state is a multipolar state having both antiferrohexadecapoles in the E representation and ferromultipoles in the B-2 representation on each Fe site. Cooperative coupling between the E and the B-2 multipoles in the local coordinate with the D-2d point group will play an important role in the formation of the d(xz), d(yz) orbital-splitting nematic state not only in FeSe, but also in other iron pnictides.

【 授权许可】

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