Flat Optical Conductivity in ZrSiS due to Two-Dimensional Dirac Bands

M. B. Schilling, L. M. Schoop, B. V. Lotsch, M. Dressel, A. V. Pronin

Research output: Contribution to journalArticlepeer-review

71 Scopus citations


ZrSiS exhibits a frequency-independent interband conductivity σ(ω)=const(ω)≡σflat in a broad range from 250 to 2500 cm-1 (30-300 meV). This makes ZrSiS similar to (quasi-)two-dimensional Dirac electron systems, such as graphite and graphene. We assign the flat optical conductivity to the transitions between quasi-two-dimensional Dirac bands near the Fermi level. In contrast to graphene, σflat is not universal but related to the length of the nodal line in the reciprocal space, k0. Because of spin-orbit coupling, the discussed Dirac bands in ZrSiS possess a small gap Δ, for which we determine an upper bound max(Δ)=30 meV from our optical measurements. At low temperatures the momentum-relaxation rate collapses, and the characteristic length scale of momentum relaxation is of the order of microns below 50 K.

Original languageEnglish (US)
Article number187401
JournalPhysical review letters
Issue number18
StatePublished - Nov 1 2017
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


Dive into the research topics of 'Flat Optical Conductivity in ZrSiS due to Two-Dimensional Dirac Bands'. Together they form a unique fingerprint.

Cite this