TRIUMF

Exp. No.

M1593 — Approved

Title of Experiment

Magnetic properties of cuprate superconductors at ultra-low temperature

Spokesperson(s) for Group

Current Members of Group

Name Institution Status % of research time devoted to experiment
J.E. Sonier Simon Fraser University Professor
K. Akintola Simon Fraser University Student (PhD)
H. Eisaki AIST Senior Research
A. Fang Simon Fraser University Student (Graduate)
A. Pal Simon Fraser University PDF

Abstract

An enduring and central open question concerning high-temperature cuprate superconductors is the nature of the mysterious pseudogap regime that exists at temperatures above the superconducting phase. Achieving an understanding of the pseudogap has long been viewed as a key to understanding high-temperature superconductivity. It is widely believed to be either a manifestation of preformed superconducting carriers (known as Cooper pairs) or some type of order that competes with superconductivity. Experimental evidence supporting the latter scenario includes polarized neutron diffraction studies that have detected the onset of an unusual intra-unit-cell (IUC) magnetic order concomitant with the pseudogap. The IUC magnetic order has been linked to a theoretical model for the cuprates, which predicts a long-range ordered phase of electron-current loop order that terminates at a quantum crictical point. However, the IUC magnetic order has yet to be detected by local magnetic probe techniques, including nuclear magnetic resonance (NMR) and muon spin rotation (muSR). Consequently, there is much uncertainty about its origin. It has been proposed that the IUC magnetic order may be fluctuating at a rate that is perhaps not observable on the time scales of these local probes. On the other hand, it may be fluctuating slow enough to be detected and characterized via a longitudinal-field muSR experiment. We aim to investigate this scenario by muSR experiments on a Bi-based cuprate high-temperature superconductor.