Propagating spinons and magnons in coupled quantum spin chains

Date

Jun 15, 2021

Time

2:50 PM - 4:20 PM

Speaker

Xianglin Ke

Affiliation

Michigan State University

Language

en

Main Topic

Physik

Other Topics

Physik

Host

D. Peets

Description

Abstract:

In conventional magnets with magnetic long range order (LRO), low-energy excitations are carried by spin waves, represented by massless bosons called magnons with S = 1. However, in one-dimensional (1D) antiferromagnetic quantum spin systems, quantum fluctuations destroy LRO. Their low-energy excitations are spinons, a fractionalized fermion with S = 1/2, instead of magnons. In quasi-1D antiferromagnets with quantum spins, magnetic excitations are carried by either magnons or spinons in different energy regimes: they do not coexist independently, nor could they interact with each other. In this seminar, I will present our recent neutron scattering and theoretical studies of a unique quasi-1D quantum spin system, Cu2(OH)3Br, which consists of weakly-coupled, ferromagnetic and antiferromagnetic alternating chains. As a result, this system shows coexistence of two different magnetic quasiparticles: the ferromagnetic chains give rise to conventional magnon excitations, while the antiferromagnetic chains yield spinons. In addition, I will show that these magnetic quasiparticles interact via weak interchain interactions, leading to gap opening of magnetic excitations and asymmetric spectral weight.

Host: D. Inosov

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Links

• Webseite
• Termindetails auf den Webseiten der TU Dresden (https://tu-dresden.de)

Last modified: Jun 15, 2021, 12:08:53 AM