Power-law liquid in high-temperature superconductors

Inspired by recent photoemission measurements, we demonstrate that the normal state of cuprate superconductors can be described by a power-law liquid, a state of matter with a power-law self-energy \Sigma^\pr\pr\sim(ω²+π²T²)^α. The scaling exponent decreases from α\sim1 in the overdoped Fermi-liquid state to α\lesssim\frac{1}{2} in the optimal and underdoped regime. We find that broad scale invariance of a power-law liquid leads to the cuprates' superconducting dome, vanishing Fermi velocity, and diverging effective mass. We propose that a power-law liquid can arise from the presence of a scale-invariant sector known as unparticles. To extend the power-law liquid framework to include the ubiquitous magnetic phases of high-T_c superconductors, we study the local-itinerant dichotomy in iron pnictides. We show that an interplay between localized moments and itinerant electrons is needed to reproduce the spin excitations observed in inelastic neutron scattering experiments. These results further our understanding of the degrees of freedom in high-T_c superconductors and will help formulate a consistent framework incorporating the physics of the antiferromagnetic, normal, and superconducting states.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2018

Author dc:creator

• Leong, Zhidong

Contributors dc:contributor

• Phillips, Philip W.
• Fradkin, Eduardo
• Abbamonte, Peter
• Gadway, Bryce

• superconductors
• cuprates
• power-law liquid
• non-Fermi liquid
• superconducting dome
• scale-invariance

Statement dc:rights

• Copyright 2018 Zhidong Leong

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/101528

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/101528