Metamaterials for Ballistic Electrons

The paper presents a metamaterial for ballistic electrons, which consists of a quantum barrier formed in a semiconductor with negative effective electron mass. This barrier is the analogue of a metamaterial for electromagnetic waves in media with negative electrical permittivity and magnetic permeability. Besides applications similar to those of optical metamaterials, a nanosized slab of a metamaterial for ballistic electrons, sandwiched between quantum wells of positive effective mass materials, reveals unexpected conduction properties, e.g. single or multiple room temperature negative differential conductance regions at very low voltages and with considerable peak-to-valley ratios, while the traversal time of ballistic electrons can be tuned to larger or smaller values than in the absence of the metamaterial slab. Thus, slow and fast electrons, analogous to slow and fast light, occur in metamaterials for ballistic electrons

The Interference Term in the Wigner Distribution Function and the Aharonov-Bohm Effect

A phase space representation of the Aharonov-Bohm effect is presented. It shows that the shift of interference fringes is associated to the interference term of the Wigner distribution function of the total wavefunction, whereas the interference pattern is defined by the common projections of the Wigner distribution functions of the interfering beamsComment: 10 pages, 4 figure

The Localized Quantum Vacuum Field

A model for the localized quantum vacuum is proposed in which the zero-point energy of the quantum electromagnetic field originates in energy- and momentum-conserving transitions of material systems from their ground state to an unstable state with negative energy. These transitions are accompanied by emissions and re-absorptions of real photons, which generate a localized quantum vacuum in the neighborhood of material systems. The model could help resolve the cosmological paradox associated to the zero-point energy of electromagnetic fields, while reclaiming quantum effects associated with quantum vacuum such as the Casimir effect and the Lamb shift; it also offers a new insight into the Zitterbewegung of material particles.Comment: 21 pages, 1 figur

Phase Space Formulation of Quantum Mechanics. Insight into the Measurement Problem

A phase space mathematical formulation of quantum mechanical processes accompanied by and ontological interpretation is presented in an axiomatic form. The problem of quantum measurement, including that of quantum state filtering, is treated in detail. Unlike standard quantum theory both quantum and classical measuring device can be accommodated by the present approach to solve the quantum measurement problemComment: 29 pages, 4 figure

Writing Electronic Devices on Paper with Carbon Nanotube Ink

The normal paper used in any printer is among the cheapest flexible organic materials that exist. We demonstrate that we can print on paper high-frequency circuits tunable with an applied dc voltage. This is possible with the help of an ink containing functionalized carbon nanotubes and water. After the water is evaporated from the paper, the nanotubes remain steadily imprinted on paper, showing a semiconducting behaviour and tunable electrical properties

Geometrical-induced rectification in two-dimensional ballistic nanodevices

The paper demonstrates that a two-dimensional ballistic nanodevice in which the electron gas satisfies either the Schroodinger equation (as in quantum wells in common semiconductor heterostructures) or the Dirac equation (as in graphene) is able to rectify an electric signal if the device has a non-uniform cross section, for instance a taper configuration. No p-n junctions or dissimilar electrodes are necessary for rectification

Optical analogue of population trapping in the continuum: classical and quantum interference effects

A quantum theory of light propagation in two optical channel waveguides tunnelling-coupled to a common continuum of modes (such as those of a slab waveguide) is presented, and classical and quantum interference effects are investigated. For classical light, the photonic system realizes an optical analogue of coherent population trapping in the continuum encountered in atomic physics, where destructive interference between different light leakage channels leads to the appearance of a trapped state embedded in the continuum. For nonclassical light, two-photon interference effects are predicted, such as the tendency of photon pairs to bunch when decaying into the continuum.Comment: 12 pages, 2 figure