arXiv subjects

J. Jacak

Publications and source records attributed to J. Jacak.

5 recordsLinked to original sources

arXiv2011

On auxiliary flux tubes associated to composite fermions in 2D Hall systems

An inaccuracy of composite fermion model is identified for Landau level fillings out of 1/p, p odd. The corrected version of hierarchy for fractional quantum Hall effect is proposed by mapping onto integer effect within the cyclotron braid approach. Flux-tubes and vortices for composite fermion constructions are explained in terms of cyclotron braids. The even denominator fractional lowest Landau level fillings, including Hall metal, are also discussed in cyclotron braid terms.

cond-mat.mes-hall↗

arXiv2010

Undamped energy transport by collective surface plasmon oscillations along metallic nanosphere chain

The random-phase-approximation semiclassical scheme for description of plasmon excitations in large metallic nanospheres (with radius 10--100 nm) is developed for a case of presence of dynamical electric field. The spectrum of plasmons in metallic nanosphere is determined including both surface and volume type excitations and their mutual connections. It is demonstrated that only surface plasmons of dipole type can be excited by a homogeneous dynamical electric field. The Lorentz friction due to irradiation of e-m energy by plasmon oscillations is analysed with respect to the sphere dimension. The resulting shift of resonance frequency due to plasmon damping is compared with experimental data for various sphere radii. Collective of wave-type oscillations of surface plasmons in long chains of metallic spheres are described. The undamped region of propagation of plasmon waves along the chain is found in agreement with some previous numerical simulations.

cond-mat.mes-hall↗

arXiv2009

Radius dependent shift of surface plasmon frequency in large metallic nanospheres: theory and experiment

Theoretical description of oscillations of electron liquid in large metallic nanospheres (with radius of few tens nm) is formulated within random-phase-approximation semiclassical scheme. Spectrum of plasmons is determined including both surface and volume type excitations. It is demonstrated that only surface plasmons of dipole type can be excited by homogeneous dynamical electric field. The Lorentz friction due to irradiation of electro-magnetic wave by plasmon oscillations is analyzed with respect to the sphere dimension. The resulting shift of resonance frequency turns out to be strongly sensitive to the sphere radius. The form of e-m response of the system of metallic nanospheres embedded in the dielectric medium is found. The theoretical predictions are verified by a measurement of extinction of light due to plasmon excitations in nanosphere colloidal water solutions, for Au and Ag metallic components with radius from 10 to 75 nm. Theoretical predictions and experiments clearly agree in the positions of surface plasmon resonances and in an emergence of the first volume plasmon resonance in the e-m response of the system for limiting big nanosphere radii, when dipole approximation is not exact.

cond-mat.mes-hall↗

arXiv2009

Surface and volume plasmons in metallic nanospheres in semiclassical RPA-type approach; near-field coupling of surface plasmons with semiconductor substrate

The random-phase-approximation semiclassical scheme for description of plasmon excitations in large metallic nanospheres, with radius range 10-60 nm, is formulated in an all-analytical version. The spectrum of plasmons is determined including both surface and volume type excitations and their mutual connections. The various channels for damping of surface plasmons are evaluated and the relevant resonance shifts are compared with the experimental data for metallic nanoparticles of different size located in dielectric medium or on the semiconductor substrate. The strong enhancement of energy transfer from the surface plasmon oscillations to the substrate semiconductor is explained in the regime of a near-field coupling in agreement with recent experimental observations for metallically nanomodified photo-diode systems.

cond-mat.mes-hall↗

arXiv2009

Cyclotron braid group approach to Laughlin correlations

Homotopy braid group description including cyclotron motion of charged interacting 2D particles at strong magnetic field presence is developed in order to explain, in algebraic topology terms, Laughlin correlations in fractional quantum Hall systems. There are introduced special cyclotron braid subgroups of a full braid group with one dimensional unitary representations suitable to satisfy Laughlin correlation requirements. In this way an implementation of composite fermions (fermions with auxiliary flux quanta attached in order to reproduce Laughlin correlations) is formulated within uniform for all 2D particles braid group approach. The fictitious fluxes-vortices attached to the composite fermions in a traditional formulation are replaced with additional cyclotron trajectory loops unavoidably occurring when ordinary cyclotron radius is too short in comparison to particle separation and does not allow for particle interchanges along single-loop cyclotron braids. Additional loops enhance the effective cyclotron radius and restore particle interchanges. A new type of 2D particles--composite anyons is also defined via unitary representations of cyclotron braid subgroups. It is demonstrated that composite fermions and composite anyons are rightful 2D particles, not auxiliary compositions with fictitious fluxes and are associated with cyclotron braid subgroups instead of the full braid group, which may open also a new opportunity for non-Abelian composite anyons for topological quantum information processing applications, due to richer representations of subgroup than of a group.

cond-mat.mes-hall↗