Occurrence of nematic, topological, and Berry phases when a flat and a parabolic band touch

B. Dóra, Igor F. Herbut, Roderich Moessner

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

A (single flavor) quadratic band crossing in two dimensions is known to have a generic instability towards a quantum anomalous Hall (QAH) ground state for infinitesimal repulsive interactions. Here we introduce a generalization of a quadratic band crossing which is protected only by rotational symmetry. By focusing on the representative case of a parabolic and flat band touching, which also allows for a straightforward lattice realization, the interaction induced nematic phase becomes the dominant instability in certain parts of the phase diagram already at weak coupling, by competing successfully with the QAH insulator. The full phase diagram of the model, together with its topological properties, is mapped out using a perturbative renormalization-group, strong-coupling analysis, the mean-field theory. Interestingly, the Berry flux varies continuously in the single flavor limit with various control parameters.

Original languageEnglish
Article number045310
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume90
Issue number4
DOIs
Publication statusPublished - Jul 24 2014

Fingerprint

touch
Flavors
Phase diagrams
occurrences
Mean field theory
phase diagrams
Ground state
Fluxes
insulators
interactions
ground state
symmetry

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Occurrence of nematic, topological, and Berry phases when a flat and a parabolic band touch. / Dóra, B.; Herbut, Igor F.; Moessner, Roderich.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 90, No. 4, 045310, 24.07.2014.

Research output: Contribution to journalArticle

@article{a8d15a10dfff42889fa2b91700a69fc6,
title = "Occurrence of nematic, topological, and Berry phases when a flat and a parabolic band touch",
abstract = "A (single flavor) quadratic band crossing in two dimensions is known to have a generic instability towards a quantum anomalous Hall (QAH) ground state for infinitesimal repulsive interactions. Here we introduce a generalization of a quadratic band crossing which is protected only by rotational symmetry. By focusing on the representative case of a parabolic and flat band touching, which also allows for a straightforward lattice realization, the interaction induced nematic phase becomes the dominant instability in certain parts of the phase diagram already at weak coupling, by competing successfully with the QAH insulator. The full phase diagram of the model, together with its topological properties, is mapped out using a perturbative renormalization-group, strong-coupling analysis, the mean-field theory. Interestingly, the Berry flux varies continuously in the single flavor limit with various control parameters.",
author = "B. D{\'o}ra and Herbut, {Igor F.} and Roderich Moessner",
year = "2014",
month = "7",
day = "24",
doi = "10.1103/PhysRevB.90.045310",
language = "English",
volume = "90",
journal = "Physical Review B-Condensed Matter",
issn = "0163-1829",
publisher = "American Physical Society",
number = "4",

}

TY - JOUR

T1 - Occurrence of nematic, topological, and Berry phases when a flat and a parabolic band touch

AU - Dóra, B.

AU - Herbut, Igor F.

AU - Moessner, Roderich

PY - 2014/7/24

Y1 - 2014/7/24

N2 - A (single flavor) quadratic band crossing in two dimensions is known to have a generic instability towards a quantum anomalous Hall (QAH) ground state for infinitesimal repulsive interactions. Here we introduce a generalization of a quadratic band crossing which is protected only by rotational symmetry. By focusing on the representative case of a parabolic and flat band touching, which also allows for a straightforward lattice realization, the interaction induced nematic phase becomes the dominant instability in certain parts of the phase diagram already at weak coupling, by competing successfully with the QAH insulator. The full phase diagram of the model, together with its topological properties, is mapped out using a perturbative renormalization-group, strong-coupling analysis, the mean-field theory. Interestingly, the Berry flux varies continuously in the single flavor limit with various control parameters.

AB - A (single flavor) quadratic band crossing in two dimensions is known to have a generic instability towards a quantum anomalous Hall (QAH) ground state for infinitesimal repulsive interactions. Here we introduce a generalization of a quadratic band crossing which is protected only by rotational symmetry. By focusing on the representative case of a parabolic and flat band touching, which also allows for a straightforward lattice realization, the interaction induced nematic phase becomes the dominant instability in certain parts of the phase diagram already at weak coupling, by competing successfully with the QAH insulator. The full phase diagram of the model, together with its topological properties, is mapped out using a perturbative renormalization-group, strong-coupling analysis, the mean-field theory. Interestingly, the Berry flux varies continuously in the single flavor limit with various control parameters.

UR - http://www.scopus.com/inward/record.url?scp=84905020305&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84905020305&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.90.045310

DO - 10.1103/PhysRevB.90.045310

M3 - Article

VL - 90

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 0163-1829

IS - 4

M1 - 045310

ER -