Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · cond-mat/0011459

Bilayer Quantum Hall States at $ν=1$ and Coulomb Drag

Yong Baek Kim·Chetan Nayak·Eugene Demler·N. Read·S. Das Sarma
View original source ↗Read source document ↗Export metadata ↓

Abstract

We consider a number of strongly-correlated quantum Hall states which are likely to be realized in bilayer quantum Hall systems at total Landau level filling fraction ${ν_T}=1$. One state, the $(3,3,-1)$ state, can occur as an instability of a compressible state in the large $d/l_B$ limit, where $d$ and $l_B$ are the interlayer distance and magnetic length, respectively. This state has a hierarchical descendent which is interlayer coherent. Another interlayer coherent state, which is expected in the small $d/l_B$ limit is the well-known Halperin $(1,1,1)$ state. Using the concept of composite fermion pairing, we discuss the wavefunctions which describe these states. We construct a phase diagram using the Chern-Simons Landau-Ginzburg theory and discuss the transitions between the various phases. We propose that the longitudinal and Hall drag resistivities can be used together with interlayer tunneling to experimentally distinguish these different quantum Hall states. Our work indicates the bilayer ${ν_T}=1$ quantum Hall phase diagram to be considerably richer than that assumed so far in the literature.

Explore related subjects

cond-mat.mes-hall

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yong Baek Kim, Chetan Nayak, Eugene Demler, N. Read, S. Das Sarma. 2000-11-28. Bilayer Quantum Hall States at $ν=1$ and Coulomb Drag. https://arxiv.org/abs/cond-mat/0011459

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↗