arXiv subjects

Keith J. Kasunic

Publications and source records attributed to Keith J. Kasunic.

4 recordsLinked to original sources

arXiv2024

Shear of the vector potential in electric-dipole radiation

Electric-dipole radiation has the well-known far-field solutions of transverse electric and magnetic (TEM) fields with peak values propagating normal to (and going to zero along) the dipole axis. The calculation of these electromagnetic fields is based on the use of the magnetic vector potential: Its time derivative and divergence for the electric field E, and its curl for the magnetic field B. In this paper, we suggest the possibility of additional radiation fields, namely, those based on the shear of the vector potential. Our results show that these shear waves have a 1/r dependence on far-field distance, with four radiative components: (1)-(3) an orthogonal triad consisting of two transverse waves and a longitudinal wave propagating along the dipole axis (analogous to an acoustic dipole); and (4) a transverse wave propagating into the same solid angle as E and B, parallel to the E-field but with one-half the magnitude of the B-field. If confirmed by experiment, possible applications include RF communications, novel biomedical sensors, and a new tool in the search for extra-terrestrial intelligence (SETI).

physics.gen-ph↗

arXiv2023

Shear of the vector potential in the Aharonov-Bohm effect

The Aharonov-Bohm (AB) effect is now largely considered to be a manifestation of geometric phase. However, by decomposing the vector-potential gradient tensor into divergence, curl, and shear components, we isolate a field/charged-particle interaction that is not dependent on local electric and magnetic fields. We show that a local shear field provides a velocity-dependent, dynamic-phase interaction in the AB effect whose predictions are consistent with all known classes of AB experiments, including interference fringe shifts, the absence of time delays along the direction of propagation, and the possibility of lateral forces.

quant-ph↗

arXiv2019

Second-order effects of the magnetic vector potential in the Aharonov-Bohm experiment

Recent experiments with the Aharonov-Bohm geometry have shown that, in addition to an electron-interference fringe shift, there is also a lateral displacement of the electron diffraction envelope. In this paper, we derive a displacement force based on a second-order expansion of the magnetic vector potential. The analysis illustrates the conservation of canonical angular momentum, where the mechanical angular momentum and field angular momentum sum to a constant of the motion; the azimuthal force required to change the mechanical momentum is thus supplied by changes in field momentum associated with the second-order vector potential term. Our results are consistent with all known Aharonov-Bohm experiments, including interference fringe shifts, lateral displacement forces, and the absence of longitudinal forces.

physics.class-ph↗

arXiv2018

Magnetic Aharonov-Bohm effects and the quantum phase shift: A heuristic interpretation

The shift in Aharanov-Bohm electron-interference fringe positions has been previously derived as resulting from phase differences induced by the magnetic vector potential, without being clear on the physical mechanism behind it. In this paper, we show that the de Broglie wavelength of the electron wavefunction is changed locally by its interaction with the vector potential. The vector potential thus acts as a quantum "phase plate", changing the phase difference between interfering electron wavefunctions in a non-dispersive, gauge-invariant manner.

quant-ph↗