Hall effect of ${\mathrm{La}}_{2\mathrm{-}\mathrm{x}}$${\mathrm{Sr}}_{\mathrm{x}}$${\mathrm{CuO}}_4$: Implications for the electronic structure in the normal state

The Hall effect has been measured at 77 K in ${\mathrm{La}}_{2\mathrm{-}\mathrm{x}}$${\mathrm{Sr}}_{\mathrm{x}}$${\mathrm{CuO}}_4$ for the range of x in which high-temperature superconductivity is observed. Below x=0.15 1/$R_H$ increases linearly with x consistent with one itinerant hole per Sr atom. (The carrier density is 2.1×${10}^{21}$ ${\mathrm{cm}}^{\mathrm{-}3}$ at x=0.15 where the superconducting transition temperature is a maximum.) Between 0.15 and 0.18 $R_H$ drops by a factor of 30, remaining undetectable for larger x. Proposed charge-density-wave models are in conflict with the data.