2,461 research outputs found
Slow cross-symmetry phase relaxation in complex collisions
We discuss the effect of slow phase relaxation and the spin off-diagonal
-matrix correlations on the cross section energy oscillations and the time
evolution of the highly excited intermediate systems formed in complex
collisions. Such deformed intermediate complexes with strongly overlapping
resonances can be formed in heavy ion collisions, bimolecular chemical
reactions and atomic cluster collisions. The effects of quasiperiodic energy
dependence of the cross sections, coherent rotation of the hyperdeformed
intermediate complex, Schr\"odinger cat states and
quantum-classical transition are studied for Mg+Si heavy ion
scattering.Comment: 10 pages including 2 color ps figures. To be published in Physics of
Atomic Nuclei (Yadernaya fizika
Thermalized non-equilibrated matter and high temperature superconducting state in quantum many-body systems
A characteristic feature of thermalized non-equilibrated matter is that, in
spite of energy relaxation--equilibration, a phase memory of the way the
many-body system was excited remains. As an example, we analyze data on a
strong forward peaking of thermal proton yield in the Bi(,p)
photonuclear reaction. New analysis shows that the phase relaxation in
highly-excited heavy nuclei can be 8 orders of magnitude or even much longer
than the energy relaxation. We argue that thermalized non-equilibrated matter
resembles a high temperature superconducting state in quantum many-body
systems. We briefly present results on the time-dependent correlation function
of the many-particle density fluctuations for such a superconducting state. It
should be of interest to experimentally search for manifestations of
thermalized non-equilibrated matter in many-body mesoscopic systems and
nanostructures.Comment: 12 pages, 1 eps figure. To be published in Radiation Effects and
Defects in Solid
Quantum-classical transition for an analog of double-slit experiment in complex collisions: Dynamical decoherence in quantum many-body systems
We study coherent superpositions of clockwise and anti-clockwise rotating
intermediate complexes with overlapping resonances formed in bimolecular
chemical reactions. Disintegration of such complexes represents an analog of
famous double-slit experiment. The time for disappearance of the interference
fringes is estimated from heuristic arguments related to fingerprints of
chaotic dynamics of a classical counterpart of the coherently rotating complex.
Validity of this estimate is confirmed numerically for the H+D chemical
reaction. Thus we demonstrate the quantum--classical transition in temporal
behavior of highly excited quantum many-body systems in the absence of external
noise and coupling to an environment.Comment: 5 pages, 2 ps color figures. Accepted for publication in Phys. Rev.
Anomalously Slow Cross Symmetry Phase Relaxation, Thermalized Non-Equilibrated Matter and Quantum Computing Beyond the Quantum Chaos Border
Thermalization in highly excited quantum many-body system does not
necessarily mean a complete memory loss of the way the system was formed. This
effect may pave a way for a quantum computing, with a large number of qubits
--1000, far beyond the quantum chaos border. One of the
manifestations of such a thermalized non-equilibrated matter is revealed by a
strong asymmetry around 90 c.m. of evaporating proton yield in the
Bi(,p) photonuclear reaction. The effect is described in terms of
anomalously slow cross symmetry phase relaxation in highly excited quantum
many-body systems with exponentially large Hilbert space dimensions. In the
above reaction this phase relaxation is about eight orders of magnitude slower
than energy relaxation (thermalization).Comment: Published in SIGMA (Symmetry, Integrability and Geometry: Methods and
Applications) at http://www.emis.de/journals/SIGMA
Experimental proposal for accurate determination of the phase relaxation time and testing a formation of thermalized non-equilibrated matter in highly excited quantum many-body systems
We estimate how accurate the phase relaxation time of quantum many-body
systems can be determined from data on forward peaking of evaporating protons
from a compound nucleus. The angular range and accuracy of the data needed for
a reliable determination of the phase relaxation time are evaluated. The
general method is applied to analyze the inelastic scattering of 18 MeV protons
from Pt for which previously measured double differential cross sections for
two angles in the evaporating domain of the spectra show a strong forward
peaking. A new experiment for an improved determination of the phase relaxation
time is proposed. The experiment is also highly desirable for an accurate test
of a formation of thermalized non-equilibrated matter in quantum many-body
systems.Comment: 5 pages, 3 figure
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