272 research outputs found
The hidden phase of Fock states; quantum non-local effects
We revisit the question of how a definite phase between Bose-Einstein
condensates can spontaneously appear under the effect of measurements. We first
consider a system that is the juxtaposition of two subsystems in Fock states
with high populations, and assume that successive individual position
measurements are performed. Initially, the relative phase is totally undefined,
and no interference effect takes place in the first position measurement. But,
while successive measurements are accumulated, the relative phase becomes
better and better known, and a clear interference pattern emerges. It turns out
that all observed results can be interpreted in terms of a pre-existing, but
totally unknown, relative phase, which remains exactly constant during the
experiment. We then generalize the results to more condensates. We also
consider other initial quantum states than pure Fock states, and distinguish
between intrinsic phase of a quantum state and phase induced by measurements.
Finally, we examine the case of multiple condensates of spin states. We discuss
a curious quantum effect, where the measurement of the spin angular momentum of
a small number of particles can induce a big angular momentum in a much larger
assembly of particles, even at an arbitrary distance. This spin observable can
be macroscopic, assimilable to the pointer of a measurement apparatus, which
illustrates the non-locality of quantum mechanics with particular clarity.Comment: a factor 1/2 added in equation (9); reference (30) completed, DOI
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Use of the industrial property system in Colombia (2018): A supervised learning application
The purpose of this paper is to establish ways to predict the spatial distribution of the use of the intellectual property system from information on industrial property applications and grants (distinctive signs and new creations) and copyright registrations in 2018. This will be done using supervised learning algorithms applied to information on industrial property applications and grants (trademarks and new creations) and copyright registrations in 2018. Within the findings, 4 algorithms were identified with a level of explanation higher than 80%: (i) Linear Regression, with an elastic network regularization; (ii) Stochastic Gradient Descent, with Hinge loss function, Ringe regularization (L2) and a constant learning rate; (iii) Neural Networks, with 1,000 layers, with Adam’s solution algorithm and 2,000 iterations; (iv) Random Forest, with 10 tree
Effect of screening of the electron-phonon interaction on the temperature of Bose-Einstein condensation of intersite bipolarons
Here we consider an interacting electron-phonon system within the framework
of extended Holstein-Hubbard model at strong enough electron-phonon interaction
limit in which (bi)polarons are the essential quasiparticles of the system. It
is assumed that the electron-phonon interaction is screened and its potential
has Yukawa-type analytical form. An effect of screening of the electron-phonon
interaction on the temperature of Bose-Einstein condensation of the intersite
bipolarons is studied for the first time. It is revealed that the temperature
of Bose-Einstein condensation of intersite bipolarons is higher in the system
with the more screened electron-phonon interaction.Comment: 6 pages, 4 figure
STUDY OF PROCESSES DURING ELECTROLYSIS OF ORGANIC DYE SOLUTION BY MEANS OF ION-PHOTON SPECTROMETRY
Spectral composition and quantum yield of radiation of the excited particles sputtered by an ion beam from surfaces of the dried sediment formed on electrodes at the electrolysis of the organic dye were studied by the method of ion-photon spectrometry. A correspondence between processes taking place near the electrode during the electrolysis of the organic dye solution and the composition of excited particles knocked out from the dried sediment formed on the electrodes was shown
Mechanism Underlying Trapping of Hydrogen Isotopes in Neutron-irradiated Plasma Facing Materials
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