Pseudogap phase of cuprate superconductors confined by Fermi surface topology

Abstract

The properties of cuprate high-temperature superconductors are largely shaped by competing phases whose nature is often a mystery. Chiefly among them is the pseudogap phase, which sets in at a doping p* that is material-dependent. What determines p* is currently an open question. Here we show that the pseudogap cannot open on an electron-like Fermi surface, and can only exist below the doping p FS at which the large Fermi surface goes from hole-like to electron-like, so that p* ≤ p FS. We derive this result from high-magnetic-field transport measurements in La1.6−xNd0.4SrxCuO4 under pressure, which reveal a large and unexpected shift of p* with pressure, driven by a corresponding shift in p FS. This necessary condition for pseudogap formation, imposed by details of the Fermi surface, is a strong constraint for theories of the pseudogap phase. Our finding that p* can be tuned with a modest pressure opens a new route for experimental studies of the pseudogap.

Effects of a k⃗-dependent Hybridisation on the Fermi surface of an extended d–p Hubbard model

“…Therefore, the present results show that both the hybridization and the doping are detrimental for the pseudogap. Such results are in agreement with recent experimental findings showing that the critical doping where the pseudogap closes is deeply affected by pressure [1]. In this sense, whereas the hybridization is susceptible to the pressure changes [22][23][24], the present results corroborate the experimental data [1] and indicates a new route for theoretical investigations of the Lifshitz transition and the pseudogap regime.…”

“…To understand the nature of the pseudogap regime present in the normal state of the hole-doped cuprates, seems to be a essential ingredient for the process of understanding the superconductivity in these systems. There are experimental evidences suggesting a close relation between the existence of the pseudogap and the topology of the Fermi surface in cuprates [1]. Both the pseudogap and the Fermi surface topology are strongly hole-doping dependent [1,2].…”

“…There are experimental evidences suggesting a close relation between the existence of the pseudogap and the topology of the Fermi surface in cuprates [1]. Both the pseudogap and the Fermi surface topology are strongly hole-doping dependent [1,2]. When doping is increased, there is a critical doping, above which, the Fermi surface topology changes from holelike to electron-like, indicating a Lifshitz transition [3][4][5].…”

“…Motivated by recent experimental results relating the peseudogap and the Fermi surface topology of cuprate superconductors [1], in the present work, a n-pole approximation [29,30] has been used to investigate the topology of the Fermi surface associated with an extended d − p Hubbard model. The study of the Fermi surface and the dispersions of bands is essential to better understand the superconducting and the normal properties of the high-T c 's [31].…”

Pseudogap, van Hove singularity, maximum in entropy, and specific heat for hole-doped Mott insulators

“…The equivalence established in Ref. [24] between applying pressure in experiments and decreasing |t | in calculations enables us to establish another analogy with Refs. [94,95]: at a given doping, the slope of C/T as a function of temperature on the semi-log plot becomes flatter with decreasing |t |, like we find by comparing the two plots in Fig.…”