77 research outputs found
Replica symmetry breaking related to a general ultrametric space II: RSB solutions and the n\to0 limit
Replica symmetry breaking solutions for the new replica anzats, related to
general ultrametric spaces, are investigated. A variant of analysis on trees is
developed and applied to the computation of the n\to0 limit in the new replica
anzats.Comment: 22 page
Interaction of 3-level atom with radiation
The stochastic limit of quantum theory suggests a new, constructive, approach to nonequilibrium phenomena. We illustrate this approach when considering the interaction of 3-level system with a quantum field
in a nonequilibrium state. We describe a class of states of the quantum field for which a stationary state drives
the system to an inversely populated state. We find that the quotient of the population of the energy levels in the
simplest case is described by the double Einstein formula which involves products of two Einstein emis-sion/absorption factors. Emission and absorption of radiation by 3-level atom in nonequilibrium stationary state
is described
Non-Exponential decay for polaron model
A model of particle interacting with quantum field is considered. The model includes as particular cases the polaron model and non-relativistic quantum electrodynamics. We compute matrix elements of the evolution operator in the stochastic approximation and show that depending on the state of the particle one can get the non-exponential decay with the rate t^{-3/2}. In the process of computation a new algebra of commutational relations that can be considered as an operator deformation of quantum Boltzmann commutation relations is used
Replica symmetry breaking related to a general ultrametric space III: the case of general measure
Family of replica matrices, related to general ultrametric spaces with
general measures, is introduced. These matrices generalize the known Parisi
matrices. Some functionals of replica approach are computed. Replica symmetry
breaking solution is found.Comment: 21 page
Noncommutative probability in classical systems
Two examples of the situation when the classical observables should be
described by a noncommutative probability space are investigated. Possible
experimental approach to find quantum-like correlations for classical
disordered systems is discussed. The interpretation of noncommutative
probability in experiments with classical systems as a result of context
(complex of experimental physical conditions) dependence of probability is
considered
Genetic code on the dyadic plane
We introduce the simple parametrization for the space of codons (triples of
nucleotides) by 8\times 8 table. This table (which we call the dyadic plane)
possesses the natural 2-adic ultrametric. We show that after this
parametrization the genetic code will be a locally constant map of the simple
form. The local constancy of this map will describe degeneracy of the genetic
code.
The map of the genetic code defines 2-adic ultrametric on the space of amino
acids. We show that hydrophobic amino acids will be clustered in two balls with
respect to this ultrametric. Therefore the introduced parametrization of space
of codons exhibits the hidden regularity of the genetic code.Comment: Some gap in the construction was fixe
Photoconductivity mechanism in structures with Ge-nanoclusters grown on Si(100) surface
Interband optical transitions in the epitaxial Si/Ge heterostructures with Ge
nanoislands grown on Si(100) surface were investigated using photocurrent
spectroscopy. The mechanism of photoconductivity was discussed. It was shown that
electron transitions from the ground state of the valence band in a quantum dot to the
conduction band of Si surrounding make the main contribution into monopolar
photoconductivity below the fundamental absorption edge of crystalline Si. Photoexcited
holes were found to be localized in Ge nanoislands inducing the lateral conductivity
changes in the near-surface depletion layer of p-Si substrate due to the field-effect
A p-Adic Model of DNA Sequence and Genetic Code
Using basic properties of p-adic numbers, we consider a simple new approach
to describe main aspects of DNA sequence and genetic code. Central role in our
investigation plays an ultrametric p-adic information space which basic
elements are nucleotides, codons and genes. We show that a 5-adic model is
appropriate for DNA sequence. This 5-adic model, combined with 2-adic distance,
is also suitable for genetic code and for a more advanced employment in
genomics. We find that genetic code degeneracy is related to the p-adic
distance between codons.Comment: 13 pages, 2 table
Quantum effects in multilayer Si-Ge nanoheterostructures
The lateral photoconductivity spectra and photofield electron emission were used to investigate multilayer Ge/Si heterostructures with Ge quantum dots. Earlier we have revealed a close connection between elastic strain in Ge quantum dots originating due to the lattice mismatch during the epitaxial growth and additional energy level forming in the strained Si-Ge heterojunction region. Thus, it appeared to be possible observing intraband transitions in Ge quantum dots that are absent in two-dimensional Si-Ge heterostructures using such simple and informative methods. While an influence of the number of Ge quantum dot layers on lateral photoconductivity spectra is not essential, the photofield electron emission characteristics showed considerable shift to middle infrared area, as the number of Ge quantum dot layers increased. It was revealed that size and composition parameters of Ge quantum dots correspond to energy levels in the valence band of the latter with the energy distance between them about 0.32 and 0.34 eV with a high accuracy. The results of our investigation make it possible to expect their possible application in new nano- and optoelectronic devices.Методами фотопольової емісії та повздовжньої фотопровідності було досліджено багатошарові наногетероструктури з квантовими точками германію. Попередні дослідження показали тісний зв'язок пружних напружень, що виникають при епітаксійному рості матеріалів з різними постійними граток, з виникненням додаткових рівнів в зоні такого гетеропереходу. Таким чином, відносно простими але інформативними методами спостерігалися міжзонні переходи, які відсутні в двовимірних гетероструктурах Si-Ge. Якщо вплив кількості шарів на фотопольову емісію несуттєвий, то при дослідженні фотопровідності виявлено прямий зв'язок зсуву чутливості повздовжньої фотопровідності в середній інфрачервоний діапазон від кількості шарів з квантовими точками германію. Показано, що розмірні характеристики та мольний склад квантових точок відповідають енергетичним рівням з енергетичною відстанню між ними приблизно 0,32 та 0,34 еВ з дуже високою точністю. Результати досліджень дозволяють сподіватися на їх використання в перспективних приладах нано- та оптоелектроніки
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