Model Hamiltonian for topological insulators

Liu, Chao Xing; Qi, Xiao Liang; Zhang, Haijun; Dai, Xi; Fang, Zhong; Zhang, Shou Cheng

doi:10.1103/physrevb.82.045122

Cited by 932 publications

(1,273 citation statements)

References 42 publications

Supporting

Mentioning

1,233

Contrasting

Unclassified

Order By: Relevance

“…Minimal number of Weyl fermions can be achieved in magnetically doped Bi 2 Se 3 and TlBiSe 2 family of materials, in which ferromagnetism has also been realized [29][30][31] . Here we adopt the four band model 32,33 with general mass terms, to describe these materials,…”

Section: Microscopic Modelmentioning

confidence: 99%

Chiral gauge field and axial anomaly in a Weyl semimetal

2013

Self Cite

View full text Add to dashboard Cite

Weyl fermions are two-component chiral fermions in (3 + 1)-dimensions. When coupled to a gauge field, the Weyl fermion is known to have an axial anomaly, which means the current conservation of the left-handed and right-handed Weyl fermions cannot be preserved separately. Recently, Weyl fermions have been proposed in condensed matter systems named as "Weyl semi-metals". In this paper we propose a Weyl semi-metal phase in magnetically doped topological insulators, and study the axial anomaly in this system. We propose that the magnetic fluctuation in this system plays the role of a "chiral gauge field" which minimally couples to the Weyl fermions with opposite charges for two chiralities. We study the anomaly equation of this sytem and discuss its physical consequences, including one-dimensional chiral modes in a ferromagnetic vortex line, and a novel plasmon-magnon coupling.

show abstract

Section: Microscopic Modelmentioning

confidence: 99%

Chiral gauge field and axial anomaly in a Weyl semimetal

2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…The effective model 8,29 describing the massless 2D Dirac fermion of a topological p-n junction reads…”

Section: Model and Resultsmentioning

confidence: 99%

Topologicalp-njunction

et al. 2012

Self Cite

View full text Add to dashboard Cite

We consider a junction between surface p-type and surface n-type on an ideal topological insulator in which carrier type and density in two adjacent regions are locally controlled by composition graded doping or electrical gating. Such junction setting on topological insulators are fundamental for possible device application. A single gapless chiral edge state localized along the junction interface appears in the presence of an external magnetic field, and it can be probed by scanning tunneling microscopy and transport measurements. We propose to realize this topological p-n junction in (Bi1−xSbx)2Te3, which has insulating bulk properties and a tunable surface state across the Dirac cone.

show abstract

“…Our algorithm, combined with accurate tight binding models that can be developed for any material via either first principles calculations or by simple empirical means, 57 can provide accurate quantitative simulations of the real experimental samples. We want to point out that, recently, the twisted boundary conditions were successfully used to compute the Chern invariant of an interacting 2-dimensional fractional Chern insulator.…”

Section: Discussionmentioning

confidence: 99%

Effect of strong disorder in a three-dimensional topological insulator: Phase diagram and maps of theZ2invariant

Leung

Prodan

2012

Phys. Rev. B

View full text Add to dashboard Cite

We study the effect of strong disorder in a 3-dimensional topological insulators with time-reversal symmetry and broken inversion symmetry. Firstly, using level statistics analysis, we demonstrate the persistence of delocalized bulk states even at large disorder. The delocalized spectrum is seen to display the levitation and pair annihilation effect, indicating that the delocalized states continue to carry the Z2 invariant after the onset of disorder. Secondly, the Z2 invariant is computed via twisted boundary conditions using an efficient numerical algorithm. We demonstrate that the Z2 invariant remains quantized and non-fluctuating even after the spectral gap becomes filled with dense localized states. In fact, our results indicate that the Z2 invariant remains quantized until the mobility gap closes or until the Fermi level touches the mobility edges. Based on such data, we compute the phase diagram of the Bi2Se3 topological material as function of disorder strength and position of the Fermi level.

show abstract

Model Hamiltonian for topological insulators

Cited by 932 publications

References 42 publications

Chiral gauge field and axial anomaly in a Weyl semimetal

Chiral gauge field and axial anomaly in a Weyl semimetal

Topologicalp-njunction

Effect of strong disorder in a three-dimensional topological insulator: Phase diagram and maps of theZ2invariant

Contact Info

Product

Resources

About