[Seminar] Dr. Kimberly Remund "SCGA for Spin-1 Magnets"

Speaker

Dr. Kimberly Remund / NYCU National Yang Ming Chiao Tung University, Taiwan

Title

SCGA for Spin-1 Magnets

Abstract

Frustrated magnetism is known to give rise to exotic and interesting phenomena. A fascinating subject is the study of magnetic material that do order, but not in the usual way. A famous example is a spin liquid and an intriguing example is a spin nematic, in which phase the dipole moments are suppressed while higher order-parameters subsist. Spin-1 are therefore interesting because they can support both dipolar and quadrupolar order phases.

Recently we developped a simple semi-classical method for calculating the dynamics of spin- 1 magnets. This method is based on an treatment of quantum spin-1 moments in the group U(3), allowing to treat both dipolar and quadrupolar moments on a equal basis and to describe their time evolution. Here we extend our U(3) description of spin-1 moments to a method called Self-Consitent Gaussian Approximation (SCGA) which assumes spins to be classical in the sense that each component is treated as an independent real variable. Originally, the SCGA is based on an O(3)-vector (dipolar) description of spins. In this talk, I show how the SCGA scheme can be naturally generalized to the u(3) framework, and since the u(3) generators capture both dipolar and quadrupolar degrees of freedom, how the u(3) based SCGA method provides a robust description of correlations in S=1 materials.

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Meeting ID: 927 8045 7892
Passcode: 252010