From underdoped to overdoped cuprates: two quantum phase transitions

TL;DR

This paper investigates the phase diagram of high-T_c cuprates, revealing two quantum phase transitions at different doping levels associated with changes in Fermi surface topology, supported by density of states calculations.

Contribution

It provides evidence for two distinct quantum phase transitions in cuprates, clarifying the critical doping points and their relation to Fermi surface topology changes.

Findings

Identification of two quantum phase transitions at different doping levels.

Critical concentrations linked to Fermi surface topology changes.

Support for multiple proposals on the cuprates phase diagram.

Abstract

Several experimental and theoretical studies indicate the existence of a critical point separating the underdoped and overdoped regions of the high-T_c cuprates' phase diagram. There are at least two distinct proposals on the critical concentration and its physical origin. First one is associated with the pseudogap formation for p<p*, with p~0.2. Another one relies on the Hall effect measurements and suggests that the critical point and the quantum phase transition (QPT) take place at optimal doping, p_{opt}~0.16. Here we have performed a precise density of states calculation and found that there are two QPTs and the corresponding critical concentrations associated with the change of the Fermi surface topology upon doping.