Quantum Hall systems having Corbino geometry are expected to have a large Peltier coefficient $\Pi_{ rr}$ in the quantum Hall plateau region. We present an analytic formula for $\Pi_{ rr}$ calculated employing the spectral conductivity obtained based on the self-consistent Born approximation. The coefficient $\Pi_{ rr}$ is shown to have a large negative (positive) value just above (below) an integer Landau-level filling, with the absolute value $|\Pi_{ rr}|$ increasing with decreasing temperature or decreasing disorder, and approaching the saw-tooth shape $- (E_{ N_\mathrm{ F} \sigma_\mathrm{ F}}-\zeta)/e$ in the limit of vanishing disorder, where $E_{ N_\mathrm{ F} \sigma_\mathrm{ F}}$ is the highest occupied Landau level and $\zeta$ is the chemical potential. As an initial attempt to experimentally observe the effect of the large $|\Pi_{ rr}|$, we measure the electron temperature $T_\mathrm{ out}$ near the outer perimeter of a Corbino disk, applying a radial dc current $I_\mathrm{ dc}$. The temperature $T_\mathrm{ out}$ is observed to increase or decrease depending on the direction of $I_\mathrm{ dc}$ and the sign of $\Pi_{ rr}$ as expected from the Peltier effect. Notably, $T_\mathrm{ out}$ becomes lower than the bath temperature for outward (inward) $I_\mathrm{ dc}$ in the region where $\Pi_{ rr} < 0$ ($\Pi_{ rr} > 0$).
Categories: cond-mat.mes-hall