Tracking a topological transition by straining ZrTe₅
Quantum oscillations tracked a change of topology as uniaxial strain reshaped the electronic bands.
Apurva Gaikwad, Liyuan Zhang and colleagues varied the strain applied to ZrTe₅ microcrystals and measured oscillations in their magnetotransport. The data traced a path from a weak to a strong topological insulator through an intermediate gapless Dirac semimetal.
The amplitude also carried information about spin. The authors found that a spin-dependent Berry phase changed with strain and influenced the oscillations normally used to infer Zeeman splitting.