Intrinsic Orbital Magnetoelectric Effect at finite temperature with the Kubo formula

Orbital magnetization (OM) is a fundamental quantity along with spin etc., however there is a theoretical difficulty from the ill-definedness of positional operator in periodic systems. In equilibrium, this difficulty is circumvented by a thermodynamic formulation, which can be applied even at finite temperature. On the other hand, quantum mechanical formalizations of the OM under external feilds such as electric field at finite temperature are ongoing problem.

Recent works have derived the obital magnetelectric coefficients (OMEC) at finite temperature (fermi surface term[1], intrinsic term in semiclassical approach[2]). In this work, we dirived the intrinsic OMEC with the Kubo formula at finite temperature. In this oral presentation, we will talk about the formalization and some application to specific models.

[1] S. Zhong et al., Phys. Rev. Lett. 116, 077201

[2] C. Xiao et al., Phys. Rev. B 103, 045401