Speaker: Eduardo H. da Silva Neto, University of British Columbia
Date & Time: November 7, 2013 14:00 - 15:00
Location: UBC, Hennings 318
Local Contact: Andrea Damascelli
Intended Audience: Graduate
Understanding the mechanism of superconductivity and its interplay with other possible ordered states in high transition temperature (Tc) cuprate superconductors remains one of the most significant challenges in all of condensed matter physics. In this talk I will discuss scanning tunneling microscopy (STM) measurements which establish the formation of charge ordering in the high-temperature superconductor Bi2Sr2CaCu2O8+x (Bi-2212). The STM results show that this charge ordering leaves a distinct signature in spectroscopic measurements, thereby indicating that it is likely related to the organization of holes in a doped Mott insulator. Doping- and temperature-dependent spectroscopic measurements, supported by resonant elastic x-ray scattering, establish the competing nature between charge ordering and superconductivity in Bi-2212. Finally, recent STM measurements have been used as evidence for electronic nematicity (C4 to C2 symmetry breaking) in the cuprates. If time permits, I will also discuss investigations of the influence of anisotropic tip structures on STM measurements, and establish, with a simple model calculation, the presence of a tunneling interference effect that induces an artificial nematic signal in conductance maps. Experimentally this effect is demonstrated to occur in different families of correlated electron systems.