Competition of Pairing and Nematicity in the Two-Dimensional Electron Gas

• Published in: arXiv.org
• Main Authors: Schreiber, Katherine A, Csáthy, Gábor A
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 21.03.2020
• Subjects: Electron gas; Electrons; Fermions; Level (quantity); Phase diagrams; Phase transitions; Physics - Mesoscale and Nanoscale Physics; Physics - Strongly Correlated Electrons
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2003.09645

Due to its extremely rich phase diagram, the two-dimensional electron gas exposed to perpendicular magnetic field has been the subject of intense and sustained study. One particularly interesting problem in this system is that of the half-filled Landau level, where the Fermi sea of composite fermions, a fractional quantum Hall state arising from a pairing instability of the composite fermions, and the quantum Hall nematic were observed in the half-filled \(N=0\), \(N=1\), and \(N \geq 2\) Landau levels, respectively. Thus different ground states developed in different half-filled Landau levels. This situation has recently changed, when evidence for both the paired fractional quantum Hall state and the quantum Hall nematic was reported in the half-filled \(N=1\) Landau level. Furthermore, a direct quantum phase transition between these two ordered states was found. These results highlight an intimate connection between pairing and nematicity, a topic of current interest in several strongly correlated systems, in a well-understood and low disorder environment.