Symmetry protected Luttinger liquids on the surface of Quantum Hall Nematics
Kartiek Agarwal
Department of Physics
McGill University
Abstract: Quantum Hall Ferromagnets are a unique platform for studying the confluence of symmetry-broken order parameter and topological physics. The novel physics of these systems was originally formulated considering the electron spin or layer index as an effective pseudospin degree of freedom that may undergo conventional symmetry breaking phenomena alongside the topological transition associated with the quantum Hall state. Experiments by Feldman et al. [1] first observed clear signatures of valley-polarized Quantum Hall Ferromagnets on the surface of Bi(111) in the presence of strong magnetic fields. More recent STM experiments [2] directly probe the excitations residing between ferromagnetic domains of opposite polarization. Curiously, domain walls appear to host low energy excitations that are gapped/gapless depending upon the filling fraction of the quantum Hall states. We explain [3] these observations both qualitatively and quantitatively, and highlight the crucial role of interactions and symmetries specific to multi-valley systems in engendering such exotic Luttinger liquids.
[1] B. Feldman et al., Science 2016
[2] M. T. Randeria, KA et al., Nature 566 (2019)
[3] KA et al., Phys Rev. B 100, 165103 (2019)
Bio: Prof. Agarwal is an Assistant Professor in the Department of Physics at McGill University in Montreal, Quebec, Canada. Prior to this, he was a postdoctoral researcher at Princeton University in Ravindra Bhatt's group. He obtained my PhD at Harvard University under the supervision of Eugene Demler.
To know more about Prof. Agarwal's research, you can consult his web page.
Cette conférence est présentée par le RQMP Versant Nord du Département de physique de l'Université de Montréal et de Génie physique de la Polytechnique.
