Local Probes for Quantum Hall Ferroelectrics and Nematics
Abstract
Two-dimensional multi-valley electronic systems in which the dispersion of individual pockets has low symmetry give rise to quantum Hall ferroelectric and nematic states in the presence of strong quantising magnetic fields. We investigate local signatures of these states arising near impurities that can be probed via Scanning Tunnelling Microscopy (STM) spectroscopy. For quantum Hall ferroelectrics, we demonstrate a direct relation between the dipole moment measured at impurity bound states and the ideal bulk dipole moment obtained from the modern theory of polarisation. We also study the many-body problem with a single impurity via exact diagonalization and find that near strong impurities non-trivial excitonic state can form with specific features that can be easily identified via STM spectroscopy.
Cite
@article{arxiv.2003.07851,
title = {Local Probes for Quantum Hall Ferroelectrics and Nematics},
author = {Pok Man Tam and Tongtong Liu and Inti Sodemann and Liang Fu},
journal= {arXiv preprint arXiv:2003.07851},
year = {2020}
}
Comments
Main: 5 pages, 4 figures; Supplement: 9 pages, 4 figures; published version