Title: Interacting spinon liquid in the magnetized antiferromagnetic spin-1/2 chain with uniform Dzyaloshinskii-Moriya interactions
Speaker: Dr. Ren-Bo Wang (Université de Montréal)
Time: 2023/08/21 (Mon.) 13:30-15:30
Place: Room 307, Cosmology Hall, NTU

Abstract:

Elementary excitations of an antiferromagnetic Heisenberg spin-½ chain are represented by neutral spin-½ spinons, which have been extensively probed by inelastic neutron scattering, electron spin and nuclear magnetic resonances, and other dynamical probes in the past. I will present our recent theoretical developments of interacting spinon liquid in the chain by utilizing both the fermion path integral and the simple hydrodynamic approach that we have developed to analyze dynamical spin susceptibilities of the chain with a uniform Dzyaloshinskii-Moriya interaction in the presence of an external magnetic field. We show that the marginally irrelevant backscattering interaction between spinons drastically changes the spectrum of spinons both qualitatively and quantitatively. All our analytical calculations compare well with numerical results obtained using matrix-product-state techniques. Furthermore, our results help to determine the magnitude of the backscattering interaction from the electron spin resonance experiments. Finally, I will show that the spinon spin current between an ideal chain and a nonmagnetic conductor in the presence of the magnetic field and a temperature gradient between them is controlled by the backscattering interaction and vanishes at the noninteracting point. All our results signify the importance of the backscattering interaction between spinons and the intriguing analogy between interacting spinon liquid in the chain and the Landau Fermi liquid of electrons in a simple metal.