Understanding High Temperature Superconductors: Progress and Prospects

TL;DR

This paper reviews progress in understanding high-temperature cuprate superconductors through measurements and microscopic calculations, emphasizing nearly anti-ferromagnetic Fermi liquid models and their implications for superconductivity mechanisms.

Contribution

It provides a comprehensive review of experimental and theoretical advances, demonstrating the NAFL model's effectiveness in explaining high Tc superconductivity phenomena.

Findings

Dynamic spin susceptibility measurements yield a new phase diagram.

NAFL pairing potential leads to d_x2-y2 pairing state.

Microscopic calculations align with experimental properties across doping levels.

Abstract

I review progress in measurements of the dynamic spin susceptibility in the normal state which yield a new phase diagram and discuss microscopic calculations which yield qualitative, and in many cases, quantitative agreement with the measured changes in the quasiparticle, transport, magnetotransport, and optical properties of the cuprate superconductors as one varies doping and temperature provided one describes the systems as nearly anti-ferromagnetic Fermi liquids in which the effective magnetic interaction between planar quasiparticles mirrors the dynamic spin susceptibility measured in NMR and INS experiments. Together with the demonstration that the NAFL pairing potential leads inexorably to a d_x2-y2,pairing state, this work provides a "proof of concept" for the NAFL description of high Tc materials. I review Eliashberg calculations of the mean-field behavior found in overdoped systems and discuss the extent to which the crossovers to pseudoscaling and pseudogap behavior found in the effective magnetic interaction and quasiparticle behavior in the optimally doped and underdoped systems may be derived microscopically. I conclude with a tentative scenario for the dependence of Tc on doping level and imperfections in different systems.