arXiv subjects

Horst von Borzeszkowski

Publications and source records attributed to Horst von Borzeszkowski.

4 recordsLinked to original sources

arXiv2001

Gravitational effects on entangled states and interferometer with entangled atoms

It is discussed how systems of quantum-correlated (entangled)particles or atoms behave in external gravitational fields and what gravitational effects may exist in such systems. An experimental setup is proposed which improves the sensitivity of the Ramsey interferometer by the usage of quantum-correlated atoms. Entanglement of $n$ atoms improves the sensitivity to small phase shifts in $n^2$ times. This scheme may be used for observing gravity-induced phase shifts in laboratory.

gr-qc↗

arXiv2000

Measurability of Electromagnetic Field: Model and Path Integral Methods

The problem of the measurability of the electromagnetic field is investigated 1) in the framework of the abstract restricted-path-integral method, and 2) by explicitly accounting the action of the field onto the meter and its back reaction. The meaning of the previously obtained results as well as of the classical results of Bohr and Rosenfeld are made clear. The restricted-path-integral method with integration over field configurations is shown to give an estimation on the measurability of the field by any device not disturbing the measured field (in the process of measurement) more than by the measurement error. Such method of measurement is necessary for the control of the field in electronic devices.

quant-ph↗

arXiv2000

Position Measurement for a Relativistic Particle: Restricted-Path-Integral Analysis

Measurements of the position of a relativistic particle is considered in the framework of the Restricted-Path-Integral (RPI) approach. The amplitude describing such a measurement is shown to be exponentially small outside the light cone of the space-time point corresponding to the measurement output, in a qualitative agreement with the Hellwig and Kraus' postulate of relativistic state reduction. Theory of the measurement including the probability distribution for different measurement outputs is suggested. It is shown that correct theory does not exist (for arbitrary initial states) if the error of the measurement is less than the Compton length. The physical reason is that the picture of measurement is destroyed in this case by pair creation.

quant-ph↗

arXiv2000

EPR effect in gravitational field: nature of non-locality

The realization of the Einstein-Podolsky-Rosen effect by the correlation of spin projections of two particles created in the decay of a single scalar particle is considered for particles propagating in gravitational field. The absence of a global definition of spatial directions makes it unclear whether the correlation may exist in this case and, if yes, what directions in distant regions must be correlated. It is shown that in a gravitational field an approximate correlation may exist and the correlated directions are connected with each other by the parallel transport along the world lines of the particles. The reason for this is that the actual origin of the quantum non-locality is founded in local processes.

quant-ph↗