Hall effect and quantum oscillation measurements on high temperature cuprate super- conductors show that underdoped compositions have small Fermi surface pockets whereas when heavily overdoped, a single much larger pocket is found. The origin of this change in electronic structure has been unclear, but may be related to the high temperature super- conductivity. Here we show that the clean overdoped single-layer cuprate Tl₂Ba₂CuO_6+δ (Tl2201) displays CDW order with a remarkably long correlation length ξ ≈ 200 Å which disappears above a hole doping of p_CDW ≈ 0.265. We show that the evolution of the electronic properties of Tl2201 as the doping is lowered may be explained by a Fermi surface reconstruction which accompanies the emergence of the CDW below p_CDW. Our results demonstrate importance of CDW correlations in understanding the electronic properties of overdoped cuprates. The figure shows (a) the Fermi surface of Th2201; (b) the phase diagram of overdoped Tl2201 and (c) the doping dependence of the Hall number.

Keywords: superconductivity, charge density wave, Fermi surface reconstruction