NM13.01.03 : Dirac or Weyl Fermions in HgTe

11:30 AM–12:00 PM Apr 3, 2018 (America - Denver)

PCC North, 200 Level, Room 228 B

Christoph Brune1 2 David Mahler2

1, NTNU Trondheim, Trondheim, , Norway
2, University Würzburg, Würzburg, , Germany

HgTe is so far mostly known for its topological insulator properties. Recently, however, it became apparent that HgTe can also host a Weyl semimetalic phase. Applying compressive strain to bulk HgTe will result in a band overlap of the Gamma-8 bands with 3-dimensional Dirac points emerging at the band crossings. The inversion symmetry breaking due to the zinc-blende crystal structure will than result in a further splitting into Weyl points. The experimental realization of such a Weyl semimetalic state relies on controlling the strain in the HgTe layer. For this purpose we developed the growth of HgTe layers on artificial substrate structures based on CdTe/ZnTe superlattices. Magnetoresistance measurements of such HgTe layers reveal a strongly anisotropic negative magnetoresistance consistent with the proposed chiral anomaly in Weyl systems.