Few-layer ZrTe₅ devices exhibit the two-dimensional integer quantum Hall effect
Protecting the flakes during fabrication made it possible to resolve a Hall plateau and a zero-energy state associated with the bulk band gap.
Exposure to air and damage during processing make transport experiments on thin ZrTe₅ difficult. By protecting the flakes, the collaboration obtained a low-temperature hole mobility of about 3,500 cm²/(V·s). At a filling factor of one, the Hall conductance approached one conductance quantum while the longitudinal conductance fell to a pronounced minimum.
Fangdong Tang fabricated the devices and performed the transport measurements. The paper credits Liyuan Zhang with helping conceive the study and analyze its data. Jürgen H. Smet of the Max Planck Institute for Solid State Research is the corresponding author. The work appeared in Nano Letters.