Possible Weyl-Kondo Semimetallic State in Disordered Mn-doped VAl3 Compounds

Dirac- or Weyl-Kondo semimetal is particularly interested in condensed matter physics because the Kondo effect induces band hybridization, resulting in a Kondo gap, contrary to the topologically protected Weyl semimetallic state. The Weyl-Kondo semimetal was theoretically proposed but not experimentally realized yet, as we know. Here we suggest a possible coexistence of the Weyl semimetal and Kondo effect in disordered Mn-doped VAl3. The VAl3 is known as a type-II Dirac semimetal. Dilute Mn-doping in the VAl3 Dirac semimetal induces a dilute Kondo effect at low temperature, confirmed by the temperature-dependent electrical resistivity, magnetic susceptibility, and specific heat measurements. The magnetic doping in Dirac semimetal breaks time-reversal symmetry, lifting the band degeneracy, manifests the Weyl semimetallic phase transition in Mn-doped VAl3. From the angle-dependent magneto-resistance measurement, we found the phase transition from Dirac-semimetal VAl3 to Weyl semimetal in Mn-doped VAl3. The Weyl-Kondo semimetal driven by dilute magnetic doping element in Dirac semimetal can be a good platform for investigating the non-trivial properties of competing effects between topological and correlated electronic states.