arXiv subjects

Lachezar S. Simeonov

Publications and source records attributed to Lachezar S. Simeonov.

6 recordsLinked to original sources

arXiv2024

Intuitive Derivation of the Coriolis Force

The major difficulty when one teaches about non-inertial reference frames in undergraduate courses on Classical Mechanics is to find an intuitive way to derive the Coriolis acceleration. Indeed, there is a factor of 2 in the formula for the Coriolis acceleration and this factor is shrouded in mystery. In this paper we not only show an intuitive way to derive the Coriolis acceleration but we also show why there is a factor of 2. Indeed, it turns out that the Coriolis acceleration results from two completely different reasons (and hence the factor of 2). The first reason is this - as the particle moves to a new position, it `sees` a different local velocity of the rotating frame. The second reason is purely geometrical - the velocity vector is subjected to purely geometrical rotation due to the rotation of the reference frame. Both of these contributions unite and they result in the Coriolis acceleration.

physics.ed-ph↗

arXiv2024

Derivation of Schrodinger's equation from the Hamilton-Jacobi and the Eikonal equations

Most authors of textbooks on quantum mechanics either postulate or sketch a short `ad hoc` derivation of Schrodinger's equation. In this work we give a detailed derivation of Schrodinger's equation from the Hamilton-Jacobi equation and the Eikonal equation in geometrical optics. We start from the historical debates on the nature of light -- whether it is a beam of particles, or waves in the aether. We derive the Eikonal equation and show the conditions when a wave can behave as a beam of particles. Then we discuss several experiments with an electron gun, that show clearly diffraction and interference of a single electron. Next, in order to explain these experiments, we derive Schrodinger's equation by comparing Hamilton-Jacobi equation in classical mechanics with the Eikonal equation in geometrical optics. To do that, we first show how to derive the wave equation from the Eikonal equation (not the other way around!). Second, we use this method to derive Schrodinger's equation from the Hamilton-Jacobi equation. Next, we derive Born's statistical rule using the early understanding of de Broglie that both particles and waves exist. Afterwards, we show that historically people preferred to remove the particles (as well as their trajectories) altogether from de Broglie's ideas but retained Born's rule (the so called Copenhagen interpretation). These derivations of the foundations of quantum mechanics do not follow precisely the history of the subject. Rather we select some early ideas and experiments in a judicious manner to present Schrodinger's equation in a logical and ordered way. We use the electron gun experiments instead of black body radiation and photoelectric effect. Our derivation may bring more light and satisfaction for the undergraduate students about the confusing and rather mysterious subject of quantum mechanics.

quant-ph↗

arXiv2022

Mechanical model of the inhomogeneous Maxwell's equations and of Lorentz transformations

We present a mechanical model of a quasi-elastic body (aether) which reproduces Maxwell's equations with charges and currents. Major criticism against mechanical models of electrodynamics is that any presence of charges in the known models appears to violate the continuity equation of the aether and it remains a mystery as to where the aether goes and whence it comes. We propose a solution to the mystery - in the present model the aether is always conserved. Interestingly it turns out that the charge velocity coincides with the aether velocity. In other words, the charges appear to be part of the aether itself. We interpret the electric field as the flux of the aether and the magnetic field as the torque per unit volume. In addition we show that the model is consistent with the theory of relativity, provided that we use Lorentz-Poincare interpretation (LPI) of relativity theory. We make a statistical-mechanical interpretation of the Lorentz transformations. It turns out that the length of a body is contracted by the electromagnetic field which the molecules of this same body produce. This self-interaction causes also delay of all the processes and clock-dilation results. We prove this by investigating the probability distribution for a gas of self-interacting particles. We can easily extend this analysis even to elementary particles.

physics.hist-ph↗

arXiv2019

Stopped and stationary light at the single-photon level inside a hollow-core fiber

An experimental platform operating at the level of individual quanta and providing strong light-matter coupling is a key requirement for quantum information processing. We report on narrowband light storage and retrieval as well as stationary light, based on electromagnetically induced transparency, for weak coherent light pulses down to the single-photon level with a signal-to-noise ratio of 59. The experiments were carried out with laser-cooled atoms loaded into a hollow-core photonic crystal fiber to provide strong light-matter coupling, thereby demonstrating the prospects for future quantum networks of such a platform.

quant-ph↗

arXiv2019

Compensation of the trap-induced quadrupole interaction in trapped Rydberg ions

The quadrupole interaction between the Rydberg electronic states of a Rydberg ion and the radio frequency electric field of the ion trap is analyzed. Such a coupling is negligible for the lowest energy levels of a trapped ion but it is important for a trapped Rydberg ion due to its large electric dipole moment. This coupling cannot be neglected by the standard rotating-wave approximation because it is comparable to the frequency of the trapping electric field. We investigate the effect of the quadrupole coupling by performing a suitable effective representation of the Hamiltonian. For a single ion we show that in this effective picture the quadrupole interaction is replaced by rescaled laser intensities and additional Stark shifts of the Rydberg levels. Hence this detrimental quadrupole coupling can be efficiently compensated by an appropriate increase of the Rabi frequencies. Moreover, we consider the strong dipole-dipole interaction between a pair of Rydberg ions in the presence of the quadrupole coupling. In the effective representation we observe reducing of the dipole-dipole coupling as well as additional spin-spin interaction.

quant-ph↗

arXiv2016

Stationary light pulses and narrowband light storage in a laser-cooled ensemble loaded into a hollow-core fiber

We report on the first observation of stationary light pulses and narrowband light storage inside a hollow-core photonic crystal fiber. Laser-cooled atoms were first loaded into the fiber core providing strong light-matter coupling. Light pulses were then stored in a collective atomic excitation using a single control laser beam. By applying a second counterpropagating control beam, a light pulse could be brought to a standstill. Our work paves the way towards the creation of strongly-correlated many-body systems with photons and applications in the field of quantum information processing.

quant-ph↗