2,699 research outputs found
Post-processing procedure for industrial quantum key distribution systems
We present algorithmic solutions aimed on post-processing for industrial
quantum key distribution systems with hardware sifting. The main steps of the
procedure are error correction, parameter estimation, and privacy
amplification. Authentication of a classical public communication channel is
also considered.Comment: 5 pages; presented at the 3rd International School and Conference
"Saint-Petersburg OPEN 2016" (Saint-Petersburg, March 28-30, 2016
Revealing quantum chaos with machine learning
Understanding properties of quantum matter is an outstanding challenge in
science. In this paper, we demonstrate how machine-learning methods can be
successfully applied for the classification of various regimes in
single-particle and many-body systems. We realize neural network algorithms
that perform a classification between regular and chaotic behavior in quantum
billiard models with remarkably high accuracy. We use the variational
autoencoder for autosupervised classification of regular/chaotic wave
functions, as well as demonstrating that variational autoencoders could be used
as a tool for detection of anomalous quantum states, such as quantum scars. By
taking this method further, we show that machine learning techniques allow us
to pin down the transition from integrability to many-body quantum chaos in
Heisenberg XXZ spin chains. For both cases, we confirm the existence of
universal W shapes that characterize the transition. Our results pave the way
for exploring the power of machine learning tools for revealing exotic
phenomena in quantum many-body systems.Comment: 12 pages, 12 figure
Underwater measurements of muon intensity
Experimental measurements of cosmic ray muon intensity deep underwater aimed at determining a muon absorption curve are of considerable interest, as they allow to reproduce independently the muon energy spectrum at sea level. The comparison of the muon absorption curve in sea water with that in rock makes it possible to determine muon energy losses caused by nuclear interactions. The data available on muon absorption in water and that in rock are not equivalent. Underground measurements are numerous and have been carried out down to the depth of approx. 15km w.e., whereas underwater muon intensity have been measured twice and only down to approx. 3km deep
Practical cryptographic strategies in the post-quantum era
We review new frontiers in information security technologies in
communications and distributed storage technologies with the use of classical,
quantum, hybrid classical-quantum, and post-quantum cryptography. We analyze
the current state-of-the-art, critical characteristics, development trends, and
limitations of these techniques for application in enterprise information
protection systems. An approach concerning the selection of practical
encryption technologies for enterprises with branched communication networks is
introduced.Comment: 5 pages, 2 figures; review pape
Universality of Brunnian (-body Borromean) four and five-body systems
We compute binding energies and root mean square radii for weakly bound
systems of and identical bosons. Ground and first excited states of
an -body system appear below the threshold for binding the system with
particles. Their root mean square radii approach constants in the limit of weak
binding. Their probability distributions are on average located in
non-classical regions of space which result in universal structures. Radii
decrease with increasing particle number. The ground states for more than five
particles are probably non-universal whereas excited states may be universal
- …