A metallic nanowire with quantized conductance was fabricated by electrochemically etching a narrow portion of a metallic wire supported on a solid substrate down to the atomic scale. The width of the nanowire was controlled flexibly by etching atoms away or depositing atoms back onto the wire with the electrochemical potential. Using a feedback loop this method can, at will, fabricate a single or an array of long-term stable nanowires with a pre-selected quantized conductance. These stable nanowires may be used in devices as digitized conductors and as sensors that detect chemicals in the air or in solutions. Using the conductance quantization as a feedback, this method may be used to fabricate nanoelectrodes by etching off the last few atoms in the thinnest portion of each nanowire. These nanoelectrodes may be connected to single molecules in molecular devices.

In this paper we present an analysis of the spin behavior of electrons propagating through a laser field. We present an experimentally realizable scenario in which spin-dependent effects of the interaction between the laser and the electrons are dominant. The laser interaction strength and incident electron velocity are in the nonrelativistic domain. This analysis may thus lead to novel methods of creating and characterizing spin-polarized nonrelativistic femtosecond electron pulses.

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We provide support for the claim that momentum is conserved for individual events in the electron double slit experiment. The natural consequence is that a physical mechanism is responsible for this momentum exchange, but that even if the fundamental mechanism is known for electron crystal diffraction and the Kapitza-Dirac effect, it is unknown for electron diffraction from nano-fabricated double slits. Work towards a proposed explanation in terms of particle trajectories affected by a vacuum field is discussed. The contentious use of trajectories is discussed within the context of oil droplet analogues of double slit diffraction. 1. Introduction. Recently we performed the electron double slit experiment, and the pattern was recorded one electron at-a-time [1]. The electron detection rate was about one electron per second. This made it possible to manually turn off the electron source after the first electron was recorded. This electron can, by chance, land in a first diffraction order (see Fig.1). This can be considered a completed single-event experiment. Often single events experiments are only considered in a probabilistic way as the best theory available to compare with, that is Quantum Mechanics, is probabilistic. Nevertheless, a quantum description also includes the correct prediction that the individual, in this case position, outcomes are eigenvalues of operators. Even more is known about single events. This becomes clear upon asking the question: "Is momentum conserved for this experiment?" We will provide support for the claim that the generally accepted answer is yes. The natural follow-up question that is the central theme of this paper is: "By what mechanism do the electron and the slit exchange momentum?" We claim that the answer is not known and that the question is a valid one. Some discussion on possible mechanism is given. In particular, the role of image charge interaction between the electron in double slit walls and the vacuum field is discussed. The proposed explanation that the double slit provides a boundary condition for the vacuum field, which in turn provides a means by which the electron trajectory exchanges momentum[2-6] with the slit is discussed within the context of the theory Stochastic Electrodynamics (SED) [2,7]. The provocative possibility of any trajectory explanation is considered in view of the well-known oil-droplet double slit analogue. The validity range of SED and the relation with the Heisenberg uncertainty relation are discussed for the Harmonic oscillator. The intent of this paper is to raise questions and discuss ongoing work that is unfinished and as of yet inconclusive.

Stochastic electrodynamics (SED) predicts a Gaussian probability distribution for a classical harmonic oscillator in the vacuum field. This probability distribution is identical to that of the ground state quantum harmonic oscillator. Thus, the Heisenberg minimum uncertainty relation is recovered in SED. To understand the dynamics that give rise to the uncertainty relation and the Gaussian probability distribution, we perform a numerical simulation and follow the motion of the oscillator. The dynamical information obtained through the simulation provides insight to the connection between the classic double-peak probability distribution and the Gaussian probability distribution. A main objective for SED research is to establish to what extent the results of quantum mechanics can be obtained. The present simulation method can be applied to other physical systems, and it may assist in evaluating the validity range of SED.