Quenching a Weyl-Kondo semimetal by magnetic field

With the advent of topology in electronic materials the number of predicted quantum phases has literally exploded. Most of them, however, still await firm experimental identification. In strongly correlated electron systems, scanning their low-temperature phase diagrams by varying a nonthermal control parameter has been instrumental in delineating phases defined by a Landau order parameter. Here we show that this approach is versatile also for strongly correlated topological phases. We use Hall effect measurements to probe how the time reversal symmetry invariant Weyl-Kondo semimetal Ce$_3$Bi$_4$Pd$_3$ transforms under magnetic-field tuning. We detect an intriguing two-stage transition, which we associate with an annihilation of the Weyl nodes, making the system more insulating, and a consecutive transition to a heavy fermion metal phase. We expect our work to stimulate tuning studies in related systems, thereby advancing the much needed identification of organizing principles for strongly correlated electronic topology.Comment: 4 figures, 19 page