Liu, XiaoxueLi, TingxinZhang, PoPfeiffer, L.N.West, K.W.Zhang, ChiDu, Rui-Rui2018-11-012018-11-012018Liu, Xiaoxue, Li, Tingxin, Zhang, Po, et al.. "Thermopower and Nernst measurements in a half-filled lowest Landau level." <i>Physical Review B,</i> 97, no. 24 (2018) American Physical Society: https://doi.org/10.1103/PhysRevB.97.245425.https://hdl.handle.net/1911/103265Motivated by the recent proposal by Potter et al. [Phys. Rev. X 6, 031026 (2016)] concerning possible thermoelectric signatures of Dirac composite fermions, we perform a systematic experimental study of thermoelectric transport of an ultrahigh-mobility GaAs/AlxGa1−xAs two-dimensional electron system at filling factor v=1/2. We demonstrate that the thermopower Sxx and Nernst Sxy are symmetric and antisymmetric with respect to B=0 T, respectively. The measured properties of thermopower Sxx at v=1/2 are consistent with previous experimental results. The Nernst signals Sxy of v=1/2, which have not been reported previously, are nonzero and show a power-law relation with temperature in the phonon-drag dominant region. In the electron-diffusion dominant region, the Nernst signals Sxy of v=1/2 are found to be significantly smaller than the linear temperature dependent values predicted by Potter et al., and decreasing with temperature faster than linear dependence.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlePhysRevB.97.245425https://doi.org/10.1103/PhysRevB.97.245425