Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1509.00210

Strong-coupling phases of 3D Dirac and Weyl semimetals. A renormalization group approach

J. Gonzalez
View original source ↗Read source document ↗Export metadata ↓

Abstract

We investigate the strong-coupling phases that may arise in 3D Dirac and Weyl semimetals under the effect of the long-range Coulomb interaction, considering the many-body theory of these electron systems as a variant of the conventional fully relativistic Quantum Electrodynamics (QED). For this purpose, we apply two different nonperturbative approaches, consisting in the sum of ladder diagrams and taking the limit of a large number N of fermion flavors. We benefit from the renormalizability that the theory shows in both cases to compute the anomalous scaling dimensions of different operators exclusively in terms of the renormalized coupling constant, allowing us to determine the precise location of the singularities signaling the onset of the strong-coupling phases. We show then that the QED of 3D Dirac semimetals has two competing effects at strong coupling. One of them is the tendency to chiral symmetry breaking and dynamical mass generation, which are analogous to the same phenomena arising in the conventional QED at strong coupling. This trend is however outweighed by the strong suppression of electron quasiparticles that takes place at large N, leading to a different type of critical point at sufficiently large interaction strength, shared also by the 3D Weyl semimetals. Overall, the phase diagram of the 3D Dirac semimetals turns out to be richer than that of their 2D counterparts, displaying a transition to a phase with non-Fermi liquid behavior which may be observed in materials hosting a sufficiently large number of Dirac or Weyl points.

Explore related subjects

cond-mat.mes-hallcond-mat.str-elhep-phhep-th

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J. Gonzalez. 2015-09-01. Strong-coupling phases of 3D Dirac and Weyl semimetals. A renormalization group approach. https://arxiv.org/abs/1509.00210

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Surface effects on the plasmons in two-dimemsional heterostructures: Application to tilted semi-Dirac materials

We derived closed-form analytic expressions for the plasmon dispersion equations for two and three monolayers embedded in a non-uniform dielectric medium with a surface. There is no electron tunneling between the layers or hybridization of the layer polarizability. The dispersion equations are deduced from calculated expressions for the corresponding surface response functions (SRFs) generated by a frequency-dependent external polarized electromagnetic field. The SRF is calculated by employing Maxwell's equations in conjunction with linear response theory.The dispersion functions reduce to well-known results for two and three monolayers embedded in a bulk medium with a uniform dielectric background. We examine the role played by a surface (i.e., homogeneous versus inhomogeneous dielectric background screening), for gapped tilted semi-Dirac materials (TSDMs) with half-linear, half-parabolic spectrums whose energy bands are tilted, anisotropic in wave vector space, and a gap is induced. The number of plasmon branches is always equal to the number of monolayer. However, the separation between these branches depends on the distance between the layers and crucially on the chosen dielectric material between the layers and whether there is air or a substrate surrounding the layered structure. For gapped TSDM, the Landau damping, i.e., Plasmon lifetime, varies from branch to branch as well as along the branch for a chosen wave vector direction. We examine these novel behaviors for two and three gapped TSDM monolayers assuming different values for the dielectric background. Our results could be useful for comparing theory with experimental data from electron energy loss spectroscopy (EELS) data.

cond-mat.mes-hall↗
arXiv2026

Microscopic Modeling of Surface Roughness Scattering in Inversion Layers of MOSFETs Based on Ando's Linear Model

Surface roughness (SR) scattering in inversion layers of bulk-MOSFETs is studied from the atomistic and quantum-mechanical viewpoints. Contrary to the usual macroscopic landscape of the roughness deviation, we introduce a stochastic deviation at each atomic site to take account of the discontinuity of the spatial derivatives of the electrostatic potential and wave-function at the semiconductor/dielectric interface, leading to an ambiguity in roughness positions. It is shown that SR parameters are consistent with those known from the experiments and, thus, there is no discrepancy problem associated with the roughness parameters in our model. The self-consistent scattering rate is derived under the framework of the Green's functions scheme: We find that the SR scattering rates are intrinsically nonlocal (non-diagonal) with respect to subband indices and greatly deviate from those based on Fermi's golden rule in the regimes of strong effective fields and/or low electron energies. As a result, the conventional SR model tends to underestimate the surface-roughness-limited mobility.

cond-mat.mes-hall↗
arXiv2026

Comparative Evaluation of Encapsulation Methods for Endohedral Doping of Single-Wall Carbon Nanotubes

Single wall carbon nanotubes (SWCNTs) are promising building blocks for nanoelectronic and optoelectronic devices, yet reliable and stable doping, particularly n type, remains challenging due to strong environmental sensitivity and competing extrinsic effects. Encapsulation of charge transfer molecules within the SWCNT cavity offers a promising route to stable doping while preserving the nanotubes outer surface for subsequent processing. Here, we systematically investigate the filling of arc discharge SWCNTs with the electron donor tetrathiafulvalene and electron acceptor tetracyanoquinodimethane, comparing different methods for filling, including melt filling, solution reflux, and vacuum phase sublimation. We follow the entire processing workflow from raw, unfilled powders to aqueous dispersions and employ density gradient ultracentrifugation to separate filled from empty nanotubes as well as metallic from semiconducting ones. Encapsulation efficiency and electronic modification are assessed using absorption spectroscopy, resonant Raman scattering, thermogravimetric analysis, X-ray photoelectron spectroscopy and electron paramagnetic resonance. Finally, we introduce a complementary vacuum-phase method that removes externally adsorbed molecules without extensive solvent washing, enabling cleaner encapsulated systems.

cond-mat.mes-hall↗