Physica B+C最新文献

Because quantum mechanics has severe interpretational problems which have not been resolved within the theory of quantum mechanics, a new approach to basic physics is proposed. Elementary particles are hypothesized to be the constructive interference peaks of a wave system extending throughout the universe. It is then shown that the wave system is in the lowest energy state when the wave modes constructively interfere. Consequently, the interference peaks are stable entities since any reduction in the constructive interference would raise the energy of the system. The Schrödinger equation is derived from the wave system based on the Lorentz invariance of the classical wave equation subject to the condition that the constructive interference peaks remain in-phase with the wave modes. In addition, the results of the two-slit interference experiment are logically explained.

The Schrödinger paradox points out that quantum mechanics predicts a linear superposition of states even for macroscopic objects prior to measurement. However, at the macroscopic level of ordinary objects it has not been possible to maintain the phase correlations needed to demonstrate or disprove the reality of such a superposition of states as opposed to the mixture of states. Without such a quantum “signature”, this paradoxical prediction of quantum theory would seem to have no testable consequences. State vector collapse in that case becomes indistinguishable from a stochastic ensemble description.

The experiment described here provides a means for testing Schrödingers' paradox. A Michelson interferometer is used to test for the presence of state superposition of a pair of shutters that are placed along the two optical arms of the interferometer and driven by a beta decay source so that either the first shutter is open and the second closed or vice versa. The shutters take on the role of the cat in the Schrödinger paradox.

The experiment that we discuss here has been carried out at SRI International. Under the conditions of the experiment, the results remove the possibility of the existence of macroscopic superposition prior to observation.

The operation of a two-thick-crystal LL neutron interferometer is strongly dependent on the size of the entrance slit as compared to the “Pendellösung length”. In the case of a narrow slit, the ray-optics formalism breaks down and the intensity profile around the center of the Borrmann fan of the second crystal, where focussing occurs, has to be calculated from the Green function which is the wave function in the observation plane for a point-source of the entrance slit, the different points of this slit being considered as incoherent. This Green function, which takes into account the presence of a test object on the beam path between the crystals, is normally a complicated integral expression. This leads to lengthy numerical calculations. It is shown that for a phase gradient φ between the crsytals, the Green function can be expressed by an expansion in terms of the Bessel functions J_2n(&φ;).

We report the results of neutron interferometric experiments, extending the range and precision of the COW gravitationally-induced quantum interference experiment of Staudenmann and co-workers. These experiments provide a test of the principle of equivalence in the quantum limit. High precision data (1 part in 1000) is presented. The frequency of the quantum interference oscillations, and the loss of contrast observed as a function of increasing gravitational potential energy difference are compared with the recent interferometer dynamical diffraction calculations of Bonse and Wroblewski and of Horne. Theory and experiment are found to differ by 0.8%.

Two different applications of matter wave interferometry are presented and discussed. The first is aimed at investigating the interference fringe shift generated by a macroscopic electric dipole. This experiment represents the electrostatic analogue of the Aharonov-Bohm effect involving time-dependent scalar potentials. The second concerns a practical application of the electron holography technique to the mapping of the total field associated with reverse biased p-n junctions.

Already in 1935, Schrödinger assembled all prerequisites for a proof of Bell-type inequalities, namely: (i) a suitable two-particle state; (ii) a sufficient number of observables which are correlated in that state; and (iii) a tentative interpretation of these correlations in the spirit of local hidden-variables theories. The inequalities derived here from these assumptions are violated in quantum mechanics, which shows once more that quantum correlations cannot be understood in terms of local hidden-variables theories. This was realized before Bell (1964), since all previous authors — including Schrödinger — focused their attention to perfect correlations and underestimated the importance of the imperfect ones.

We have measured the phase shift of a neutron de Broglie wave induced by the motion of Sm-149 through which the neutron is propagating. This experiment differs from a number of ‘neutron Fizeau’ experiments carried out in recent years. The observed phase shift is caused by the motion of the matter itself, and not by the motion of its boundaries, as was the case with the earlier experiments. In this regard our experiment is a true neutron analog of the famous Fizeau experiment of 1859, where phase shift of the light wave interference pattern was induced by the motion of matter.

Previous studies on the one-dimensional motion of neutral spin $\text{1}\text{2}$ particles with an anomalous magnetic moment in magnetic fields in nonrelativistic [1] and relativistic [2] cases are extended to two- and three-dimensional motions. Dirac equation with Pauli coupling is solved exactly.

A topological phase factor arising from the homotopy theory of path integrals in multiply connected spaces is equivalent to the non-integrable phase of the Dirac wave function of a charge particle in the presence of an inaccessible, time-independent magnetic flux. The Aharonov-Bohm interference is analysed with the topological phase.