Electrically tunable RKKY interaction in Dirac semimetals
Phys. Rev. B 113, 085145 – Published 24 February, 2026
DOI: https://doi.org/10.1103/5nyw-3tb7
Abstract
We develop a theory based on nonequilibrium Green's functions to describe indirect magnetic interactions in systems subjected to external fields. Using this framework, we investigate the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in Dirac semimetals under the influence of both electric and magnetic fields. We show that these fields induce the Berry connection, the orbital magnetic moment, and the Berry curvature dipole in the nonequilibrium Green's function, driving the system out of equilibrium. In the nonequilibrium regime, four distinct types of RKKY interactions emerge: Heisenberg, Dzyaloshinskii-Moriya, Ising, and spin-frustrated interactions, all of which are tunable by the electric field. Notably, the electric field not only renormalizes the Heisenberg term but also introduces new components into the Ising and Dzyaloshinskii-Moriya interactions. The spin-frustrated interaction, arising from the spin-momentum locking of itinerant electrons, is unique to the nonequilibrium regime and allows for the manipulation of local magnetic moments to align at arbitrary relative angles under electric field control. Our findings provide a method for electrically engineering RKKY interactions and a technique for detecting the chiral anomaly.
