Fluctuating Charge Order in the Optimally-Doped High Temperature Superconductor, Bi2Sr2CaCu2O8+x

Condensed Matter Seminars

Speaker: Peter Abbamonte, University of Illinois
Date & Time: May 26, 2016, 11:00 - 12:00
Location: AMPEL 311
Local Contact: George Sawatzky
Intended Audience: Graduate

The field of high temperature superconductivity has been revolutionized by the recent discovery of charge order in most families of underdoped copper‐oxides. There are still fundamental mysteries, however, about how this order is related to superconductivity, i.e., whether it is present at optimal doping, whether it is static or fluctuating, etc.

In this talk I will present the first results from a new, momentum-resolved, electron energy-loss spectroscopy (M-EELS) study of charge order in optimally doped high temperature superconductor, Bi2Sr2CaCu2O8+x, carried out with energy resolution dE = 4.5 meV. We observed the emergence at low temperature of diffuse, short‐ranged charge order that undergoes quasielastic fluctuations on a timescale tau = 160 fs. This order interacts with several bosonic collective modes whose spectral weight provides a transparent understanding of the so‐called “kink” structure observed with photoemission in this material. Our study suggests that superconductivity in the copper‐oxides coexists with a dynamic, inhomogeneous state that influences the magnitude of electron‐boson interactions.