Magnetic Weyl Kondo semimetal induced by quantum fluctuations

Weyl-Kondo semimetals arise from the Kondo effect cooperating with lattice symmetry [1,2]. While the Kondo effect is typically suppressed by magnetic order, we develop a theory of magnetic Weyl–Kondo semimetals [3]. The key to the proposed mechanism is that the local f moments can still fluctuate when the magnetic order comes from the conduction d electrons. We illustrate the extreme case where this happens through the constraints of the magnetic space group symmetries. Topological degeneracies, including hourglass Weyl-Kondo nodal lines, appear. Correspondingly, nonlinear anomalous Hall responses appear from first to third order.  We present several candidate materials, the most prominent of which are antiferromagnetic UNiGa and UNiAl and ferromagnetic USbTe and CeCoPO. Our findings pave the way for experimental and theoretical investigations that promise to further advance strongly correlated topology.

[1] H.-H. Lai, S. E. Grefe et al., PNAS 115, 93 (2018).

[2] S. Dzsaber et al., PNAS 118, e2013386118 (2021).

[3] Y. Fang et al., arxiv:2403.02295.