Propagating spinons and magnons in coupled quantum spin chains

Datum

15.06.2021

Zeit

14:50 - 16:20

Sprecher

Xianglin Ke

Zugehörigkeit

Michigan State University

Sprache

en

Hauptthema

Physik

Andere Themen

Physik

Host

D. Peets

Beschreibung

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

BigBlueButton:

https://selfservice.zih.tu-dresden.de/l/link.php?m=118900&p=e819ae07 (https://selfservice.zih.tu-dresden.de/l/link.php?m=118900&p=e819ae07) (TUD)

https://selfservice.zih.tu-dresden.de/link.php?m=118900&p=d3a426d2 (https://selfservice.zih.tu-dresden.de/link.php?m=118900&p=d3a426d2) (external)

Links

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

Letztmalig verändert: 15.06.2021, 00:08:53