English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In this paper we study transport properties of electrons on thetwo-dimensional honeycomb lattice. We consider a half-filled system in thevicinity of a symmetry-breaking transition from a semimetallic phase towards aninsulating phase with either charge density or spin density wave order. Theeffect of either order is to break the sublattice inversion symmetry whichinduces a finite gap for the electronic single-particle excitations.Phenomenologically, such a scenario is described in the framework of aGross-Neveu theory. We analyze two related formulations of the model by meansof (i) a controlled renormalization group calculation and (ii) the large-Nmethod, both of which in combination with a Boltzmann transport equation. Wedetermine the quantum-critical conductivity and also discuss crossover behaviorfrom quantum critical behavior into the insulating and/or the semimetallicphases. We find that at asymptotically low temperatures the quantum-criticalconductivity is given by a temperature independent universal number. Over alarge temperature window the temperature independent quantum criticalconductivity is masked by a logarithmically temperature dependent contributiondue to the marginally irrelevant long-range Coulomb interaction. We discusspossible origins of this peculiarity in the two complementary formulations ofthe model. Furthermore, we consider possible relations of our findings torecent experiments, with a special emphasis on thequantum-critical-to-insulator crossover. We find that our results are inremarkably good qualitative and quantitative agreement with a recent analysisof the data sets under the hypothesis of an underlying gap in thesingle-particle spectrum.

Quantum-Critical transport at a semimetal-to-insulator transition on the honeycomb lattice