Observation of a nematic quantum Hall liquid on the surface of bismuth

Benjamin E Feldman; Mallika T Randeria; András Gyenis; Fengcheng Wu; Huiwen Ji; R J Cava; Allan H MacDonald; Ali Yazdani

doi:10.1126/science.aag1715

Observation of a nematic quantum Hall liquid on the surface of bismuth

Science. 2016 Oct 21;354(6310):316-321. doi: 10.1126/science.aag1715.

Authors

Benjamin E Feldman¹, Mallika T Randeria¹, András Gyenis¹, Fengcheng Wu², Huiwen Ji³, R J Cava³, Allan H MacDonald², Ali Yazdani⁴

Affiliations

¹ Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA.
² Department of Physics, University of Texas, Austin, TX 78712, USA.
³ Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
⁴ Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA. yazdani@princeton.edu.

PMID: 27846563
DOI: 10.1126/science.aag1715

Abstract

Nematic quantum fluids with wave functions that break the underlying crystalline symmetry can form in interacting electronic systems. We examined the quantum Hall states that arise in high magnetic fields from anisotropic hole pockets on the Bi(111) surface. Spectroscopy performed with a scanning tunneling microscope showed that a combination of single-particle effects and many-body Coulomb interactions lift the six-fold Landau level (LL) degeneracy to form three valley-polarized quantum Hall states. We imaged the resulting anisotropic LL wave functions and found that they have a different orientation for each broken-symmetry state. The wave functions correspond to those expected from pairs of hole valleys and provide a direct spatial signature of a nematic electronic phase.

Publication types

Research Support, Non-U.S. Gov't