Ruderman-Kittel-Kasuya-Yosida interaction in Weyl semimetals

Abstract

We theoretically demonstrate the Ruderman-Kittel-Kasuya-Yosida interaction between magnetic impurities that is mediated by the Weyl fermions embedded inside a three-dimensional Weyl semimetal (WSM). The WSM is characterized by a pair of Weyl points separated in the momentum space. Using the Green's function method and a two-band model, we show that four terms contribute to the magnetic impurity interaction in the WSM phase: the Heisenberg, DzyaloshinskyMoriya, spin-frustrated and Ising terms. Except the last term which is vanishingly small in the plane perpendicular to the line connecting two Weyl points, all the other interaction terms are finite. Furthermore, the magnetic spins of the Dzyaloshinsky-Moriya and spin-frustrated terms lie in the plane perpendicular to the line connecting two Weyl points, but in this plane, the magnetic spins of the Ising term have no components. For each contribution, an analytical expression is obtained, falling off with a spatial dependence as R −5 at Weyl points and showing beating behavior that depends on the direction between two magnetic impurities.

Cr doping induced negative transverse magnetoresistance in Cd3As2 thin films

“…An external magnetic field or magnetic doping can implement the breaking of the time-reversal symmetry. A few theoretical studies have predicted a Ruderman-Kittel-Kasuya-Yosida interaction and a Kondo effect among the magnetic impurities in both Dirac and Weyl semimetals [34][35][36][37], although the experimental evidence remains lacking.…”

Resonance states and beating pattern induced by quantum impurity scattering in Weyl/Dirac semimetals

“…Note that even for STR-broken case due to finite , is diagonal in spin space and independent of , remarkably different from the case of 2D topological insulator or graphene3341. For we can calculate by expanding the in terms of spherical harmonics according to the Rayleigh equation2442, and finally arrive at a simple analytical expression for D  ≫  ω as…”

“…On one hand, the unique 3D spin-momentum locking can mediate the interaction between magnetic impurities in both Dirac and Weyl semimetals, leading to anisotropic Ruderman-Kittel-Kasuya-Yosida (RKKY) coupling and rich spin textures222324. On the other hand, the feedback effect of impurities on host bulk states can change the property of Weyl nodes, at which the differences between a Weyl phase and a normal metal are most pronounced.…”

Patterns of Organics on Substrates with Metallic Surface States: Why?, So??

“…(1); however, if the same is thin, complementary Fermi arcs on the opposite side allow nested backscattering and strong Friedel oscillations [22]. Recent work [23,24] on RKKY interactions between magnetic adatoms on Weyl semimetals find that there are four contributions from Heisenberg, Dzyaloshinsky-Moriya, spin-frustrated, and Ising couplings. A detailed discussion with implications for non-magnetic adatoms is beyond the scope of this proceedings paper.…”

“…Furthermore, the richness of the lateral interactions and geometries have long enticed engineer self-assembled patterns [1]. * This paper was presented at the 8th International Symposium on Surface Science, Tsukuba International Congress Center, Tsukuba, Japan, October [22][23][24][25][26]2017. † Corresponding author: einstein@umd.edu…”