Particle-hole asymmetry in fluctuating thermoelectric and Hall effects

Thermoelectric and Hall currents arise due to particle-hole asymmetry (PHA) in the electron system. Quadratic electron spectrum alone is a source of PHA. This asymmetry, not associated with expansion of the density of states (DOS) near the Fermi surface, leads to singular fluctuation thermopower and Hall conductivity in electron systems with two-dimensional spectrum. In impure films new contributions dominate over the contributions due to DOS expansion by parameter (T_cτ)^-1, where τ is the electron-impurity scattering time. In agreement with experimental observations in high-T_c cuprates, sign of the fluctuation Hall correction is opposite to the sign of the Hall conductivity in the normal state.