Quantum Hall ferromagnetism in graphene: a SU(4) bosonization approach

Physics – Condensed Matter – Mesoscale and Nanoscale Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

16 pages, 4 figures, final version, extended discussion about the boson-boson interaction and its relation with quantum Hall s

Scientific paper

10.1103/PhysRevB.76.195431

We study the quantum Hall effect in graphene at filling factors \nu = 0 and \nu = \pm, concentrating on the quantum Hall ferromagnetic regime, within a non-perturbative bosonization formalism. We start by developing a bosonization scheme for electrons with two discrete degrees of freedom (spin-1/2 and pseudospin-1/2) restricted to the lowest Landau level. Three distinct phases are considered, namely the so-called spin-pseudospin, spin, and pseudospin phases. The first corresponds to a quarter-filled (\nu =-1) while the others to a half-filled (\nu = 0) lowest Landau level. In each case, we show that the elementary neutral excitations can be treated approximately as a set of n-independent kinds of boson excitations. The boson representation of the projected electron density, the spin, pseudospin, and mixed spin-pseudospin density operators are derived. We then apply the developed formalism to the effective continuous model, which includes SU(4) symmetry breaking terms, recently proposed by Alicea and Fisher. For each quantum Hall state, an effective interacting boson model is derived and the dispersion relations of the elementary excitations are analytically calculated. We propose that the charged excitations (quantum Hall skyrmions) can be described as a coherent state of bosons. We calculate the semiclassical limit of the boson model derived from the SU(4) invariant part of the original fermionic Hamiltonian and show that it agrees with the results of Arovas and co-workers for SU(N) quantum Hall skyrmions. We briefly discuss the influence of the SU(4) symmetry breaking terms in the skyrmion energy.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Quantum Hall ferromagnetism in graphene: a SU(4) bosonization approach does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Quantum Hall ferromagnetism in graphene: a SU(4) bosonization approach, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quantum Hall ferromagnetism in graphene: a SU(4) bosonization approach will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-677168

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.