Datensatz

Zusammenfassung

A versatile methodology to detect topological quasiparticles by transport measurements remains an open problem. Here, the authors propose and experimentally observe the temperature dependence of the quantum oscillation frequency as a signature of non-trivial band topology.
The phase offset of quantum oscillations is commonly used to experimentally diagnose topologically nontrivial Fermi surfaces. This methodology, however, is inconclusive for spin-orbit-coupled metals where pi-phase-shifts can also arise from non-topological origins. Here, we show that the linear dispersion in topological metals leads to a T-2-temperature correction to the oscillation frequency that is absent for parabolic dispersions. We confirm this effect experimentally in the Dirac semi-metal Cd3As2 and the multiband Dirac metal LaRhIn5. Both materials match a tuning-parameter-free theoretical prediction, emphasizing their unified origin. For topologically trivial Bi2O2Se, no frequency shift associated to linear bands is observed as expected. However, the pi-phase shift in Bi2O2Se would lead to a false positive in a Landau-fan plot analysis. Our frequency-focused methodology does not require any input from ab-initio calculations, and hence is promising for identifying correlated topological materials.