Magneto-thermopower in semimetallic WTe2 thin flakes

WTe2 is the first among the series of semimetals recently discovered to possess the giant non saturating magnetoresistance. Carrier mobilities and carrier concentrations obtained from magnetoresistance and Hall resistivity, using a semi-classical two band model, show an almost full compensation between electrons and holes. We have studied thermopower (S), which is directly related to the energy derivative of the electrical conductivity at the Fermi energy EF via Mott’s relation when 𝑘𝑇 ≪𝐸F (𝑘=Boltzmann’s constant; T = Temperature), in WTe2 thin flakes. In such a compensated system a small Seebeck effect, but an extraordinary large Nernst effect is expected. Measurements of thermopower are however very challenging and a special care must be taken to rule out any additional contributions. In my talk, I will present and discuss our recent results of the magneto-transport and magneto-thermoelectric properties of thin flakes of WTe2.