Electron pockets and pseudogap asymmetry observed in the thermopower of underdoped cuprates
1 School of Chemical and Physical Sciences, Victoria University - P.O. Box 600, Wellington, New Zealand
2 MacDiarmid Institute - Callaghan Innovation, P.O. Box 31310, Lower Hutt, New Zealand
Received: 6 March 2013
Accepted: 19 April 2013
We calculate the diffusion thermoelectric power of high-Tc cuprates using the resonating-valence-bond spin-liquid model developed by Yang, Rice and Zhang (YRZ). In this model, reconstruction of the energy-momentum dispersion results in a pseudogap in the density of states that is heavily asymmetric about the Fermi level. The subsequent asymmetry in the spectral conductivity is found to account for the large magnitude and temperature dependence of the thermopower observed in underdoped cuprates. In addition we find evidence in experimental data for electron pockets in the Fermi surface, arising from a YRZ-like reconstruction, near the onset of the pseudogap in the slightly overdoped regime.
PACS: 74.72.Gh – Hole-doped / 74.72.Kf – Pseudogap regime / 74.25.fg – Thermoelectric effects
© EPLA, 2013