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arXiv · 1507.03251

SU(3) Quantum Hall Ferromagnetism in SnTe

Xiao Li·Fan Zhang·A. H. MacDonald
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Abstract

The (111) surface of SnTe hosts one isotropic $\barΓ$-centered and three degenerate anisotropic $\bar{M}$- centered Dirac surface states. We predict that a nematic phase with spontaneously broken $C_3$ symmetry will occur in the presence of an external magnetic field when the $N=0$ $\bar{M}$ Landau levels are $1/3$ or $2/3$ filled. The nematic state phase boundary is controlled by a competition between intravalley Coulomb interactions that favor a valley-polarized state, and weaker intervalley scattering processes that increase in relative strength with magnetic field. An in-plane Zeeman field alters the phase diagram by lifting the three-fold $\bar{M}$ Landau level degeneracy, yielding a ground state energy with $2π/3$ periodicity as a function of Zeeman-field orientation angle.

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Xiao Li, Fan Zhang, A. H. MacDonald. 2015-07-12. SU(3) Quantum Hall Ferromagnetism in SnTe. https://doi.org/10.1103/physrevlett.116.026803

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