Hall effect in hole doped cupates

There is an interesting $T$ dependence in the Hall coefficient ^[1], as shown in Fig 1. One can estimate the density of holes, $n_{\rm H}$, from measurements of the Hall coefficient with the formula $R_{\rm H}=1/n_{\rm H}ec$. The data imply that $n_{\rm H}$ increases with temperature. The temperature-dependent Hall effect data with the formula ^[2]
$$n_{\rm H}(x,T) = n_0(x) + n_1(x)e^{-\Delta(x)/T}.$$

As shown in Fig. 2, the temperature-independent component, $n_0$, is proportional to $x$ for low doping. The gap $\Delta$ for the thermally-excited carriers is shown in Fig.3; it is quantitatively quite similar to the antinodal pseudogap from ARPES measurements.

References

1. Y. Ando, Y. Kurita, S. Komiya, S. Ono, and K. Segawa, Phys. Rev. Lett. 92, 197001 (2004).
2. L. P. Gor’kov, and G. B. Teitel’baum, Phys. Rev. Lett. 97, 247003 (2006).