Beyond topology in TaAs*

Topological Weyl and Dirac semimetals have excited much research interest in the last few years. Much of the study of these materials has focused on the existence of exotic signatures of topology, such as Fermi arc surface states, nonlocal transport, and observations of boundary effects such as the quantum Hall effect. One feature shared by many of these materials is a low carrier density. Landau quantization in low carrier density topological semimetals in moderate magnetic fields produces large changes in the band structure of these materials, allowing the formation of tunable, strongly interacting correlated states. We present thermal and thermodynamic signatures of these strong correlations in the prototypical Weyl semimetal TaAs.