2,434 research outputs found
Narrow muon bundles from muon pair production in rock
We revise the process of muon pair production by high-energy muons in rock
using the recently published cross-section. The three-dimensional Monte Carlo
code MUSIC has been used to obtain the characteristics of the muon bundles
initiated via this process. We have compared them with those of conventional
muon bundles initiated in the atmosphere and shown that large underground
detectors, capable of collecting hundreds of thousands of multiple muon events,
can discriminate statistically muon induced bundles from conventional ones.
However, we find that the enhancement of the measured muon decoherence function
over that predicted at small distances, recently reported by the MACRO
experiment, cannot be explained by the effect of muon pair production alone,
unless its cross-section is underestimated by a factor of 3.Comment: 10 pages, 1 table, 2 figures, to be published in Physics Letters
Nonlinear dissipation can combat linear loss
We demonstrate that it is possible to compensate for effects of strong linear
loss when generating non-classical states by engineered nonlinear dissipation.
We show that it is always possible to construct such a loss-resistant
dissipative gadget in which, for a certain class of initial states, the desired
non-classical pure state can be attained within a particular time interval with
an arbitrary precision. Further we demonstrate that an arbitrarily large linear
loss can still be compensated by a sufficiently strong coherent or even thermal
driving, thus attaining a strongly non-classical (in particular,
sub-Poissonian) stationary mixed states.Comment: Submitted to PR
Quantum nature of Gaussian discord : experimental evidence and role of system-environment correlations
L.M. acknowledges Project No. P205/12/0694 of Czech Science Foundation (GACR). N.K. is grateful for the support provided by the A. von Humboldt Foundation. N.Q. and N.K. acknowledge the support from the Scottish Universities Physics Alliance (SUPA) and the Engineering and Physical Sciences Research Council (EPSRC). The project was supported within the framework of the BMBF grant “QuORep” and in the framework of the International Max Planck Partnership (IMPP) with Scottish Universities.We provide experimental evidence of quantum features in bipartite states classified as entirely classical according to a conventional criterion based on the Glauber P function but possessing nonzero Gaussian quantum discord. Their quantum nature is experimentally revealed by acting locally on one part of the discordant state. We experimentally verify and investigate the effect of discord increase under the action of local loss and link it to the entanglement with the environment. Adding an environmental system purifying the state, we unveil the flow of quantum correlations within a global pure system using the Koashi-Winter inequality. For a discordant state generated by splitting a state in which the initial squeezing is destroyed by random displacements, we demonstrate the recovery of entanglement highlighting the role of system-environment correlations.Publisher PDFPeer reviewe
Nonclassical states of the second optical harmonic in the presence of self-action
The quantum theory of coherent radiation frequency doubling in crystals with quadratic and cubic optical nonlinearities is developed. The possibility of producing the quadrature-squeezed state of the second harmonic (SH) field is shown. The nonclassical SH states arise due to self-action effect
Features of intra population variability of Medicago varia Mart. with the expressed mf-mutation on a complex qualitative characteristics
The purpose of this work was studying of features of intra population variability of a lucerne with a mf-mutation on a complex of the qualitative signs, valuable as for the forage production as well as for the pharmaceutical industr
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