[Seminar] Dr. Kirill Povarov "Probing spinons by Electron Spin Resonance: hidden interactions in a spin chain"

Speaker

Dr. Kirill Povarov / Laboratory for Solid State Physics, ETH Zurich

Graduated as MSc from Moscow Institute for Physics and Technology in 2010. Spent the PhD years 2010-2013 at the Kapitza Institute for Physical Problems (Russian Academy of Sciences, Moscow) doing ESR spectroscopy of quantum magnets. After obtaining the PhD have joined to Prof. Zheludev’s Neutron Scattering and Magnetism group at ETH Zurich as a postdoc, continuing neutron and thermodynamic experiments on various exotic magnetic systems. Since 2016 holds a position of Senior Research Assistant (Oberassistent) within the same group.  

Title

Probing spinons by Electron Spin Resonance: hidden interactions in a spin chain

Abstract

In systems that have full rotational symmetry the Electron Spin Resonance is a relatively dull phenomenon. All that one gets to observe is the magnetic precession at Larmor frequency, no matter how exotic the ground state is. However, in the quantum spin chains with a peculiar uniform pattern of Dzyaloshinskii-Moriya anisotropic interaction a fine structure of the ESR response emerges, revealing the fermionic nature of elementary excitations known as spinons. Furthermore, the details of this fine structure evolution in the magnetic field directly point at the recently predicted analogue of Fermi liquid's Silin wave in this exotic 1D fermionic system. From the experimental spectra we are able to obtain the spinon backscattering interaction constant, which does not normally manifest itself in the low-energy properties. 

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Meeting ID: 989 0330 4616