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Báze vlnových balíků v popisu rezonančního rozptylu
Lukeš, Petr ; Kolorenč, Přemysl (advisor) ; Houfek, Karel (referee)
Title: Wave-packet basis in the description of the resonance scattering Author: Petr Lukeš Institute: Institute of Theoretical physics Supervisor: RNDr. Přemysl Kolorenč, Ph.D., Institute of Theoretical Physics Abstract: A common approach towards the solution of problems of particle scattering problems is the approximation of the wavefunctions with some set of square integrable functions. A new type of such basis is assessed in this work. The vectors of the basis are obtained by integration of eigenvectors of free Hamiltonian over finite intervals of energies. This basis is called the wave- packet basis. This basis is used to compute values of resonance width and resonant energy for two simple cases and the results are compared to benchmark data known from other works. The results serve to evaluate the properties of this basis. Also this work contains a proposal of how could this basis be applied in computations of quantum scattering. Keywords: potential scattering, wave-packet basis, resonance width, resonant energy.
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Quantum mechanical study of the electron hoping processes of pigments from photosystems. Simulation of absorption and emission photoelectron spectra.
Cajzl, Radim ; Burda, Jaroslav (advisor) ; Slavíček, Petr (referee)
Title: Quantum mechanical study of the electron hoping processes of pig- ments from photosystems. Simulation of absorption and emission photoelectron spectra. Author: Bc. Radim Cajzl Department: Department of Chemical Physics and Optics Supervisor: prof. RNDr. Ing. Jaroslav Burda, DrSc., Department of Chemical Physics and Optics Abstract: The aim of this thesis is to develop a methodology for simulation of dynamical properties of carotenoids by OMx method combined with surface electron hopping. We use linear conjugated polyenes: ethene, butadiene, hexa- triene up to polyenes with 22 carbon atoms as model systems. First, the spectra are calculated with sufficiently good agreement with the experimental data by both correct order of excited states and small deviation from experimental data. These results are used for electron surface hopping for calculation of mean lifetimes of excited states of studied polyenes. Calculated lifetimes are of the same order as experimental data for butadiene, hexatriene and octatetraene. Calculated lifetimes for poleynes with 20 resp. 22 carbon atoms agree well with chemically analogous carotenoids. Keywords: quantum mechanics, photoelectron spectra, pigments of photosys- tems, elecrton transitions, molecular and electronic dynamics
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Studies of Lanthanide Complexes by a Combination of Spectroscopic Methods
Krupová, Monika ; Bouř, Petr (advisor) ; Kapitán, Josef (referee)
Studies of Lanthanide Complexes by a Combination of Spectroscopic Methods Monika Krupová (Department of Physical and Macromoecular Chemistry, Faculty of Science, Charles University in Prague) Since conventional structural analysis offers rather limited means for the chirality detection, a series of lanthanide tris-(β-diketonates) are investigated as effective receptors for a better chirality sensing in biomolecular substrates. These lanthanide complexes containing β-diketonate ligands are electrically neutral; they can further coordinate with various small organic molecules such as chiral alcohols, amino alcohols or amino acids in organic solvents and produce a strong chiral signal. Previously, a resonance in Raman scattering was observed in the studied systems due to the correspondence of europium electronic transition energy to the laser excitation wavelength, about a 100-fold signal enhancement if compared to non-resonant vibrational ROA was observed. This enabled shorter detection times as well as lower sample concentrations. In the current work, interaction of the Eu(FOD) complex with (R)- and (S)- enantiomer of 1-phenylethanol in n-hexane was studied using IR spectroscopy, Raman spectroscopy and Raman optical activity (ROA), UV-Vis spectroscopy and ultraviolet circular dichroism (UVCD). Only...
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Quantum computing in many-body physics
Brandejs, Jan ; Cejnar, Pavel (advisor) ; Knapp, František (referee)
Název práce: Kvantové výpočty v mnohočásticové fyzice Autor: Jan Brandejs Katedra: Ústav částicové a jaderné fyziky Vedoucí bakalářské práce: prof. RNDr. Pavel Cejnar, Dr., DSc., Ústav částicové a jaderné fyziky Abstrakt: Při simulaci mnohočásticových kvantových systém· obvykle dochází k exponenciální explozi výpočetní složitosti. Kvantové počítače umožňují ten- to problém principiálně vyřešit. Díky práci R. Feynmanna je známo, že axiomy teorie složitosti vychází z fyzikálních zákon·. Situace se změní, zavedeme-li do výpočetního procesu mimo klasické fyziky i kvantovou teorii. Ukazuje se, že pro efektivní simulaci kvantového systému je vhodné použít jiný, lépe kontrolovatelný kvantový systém. Realizace výpočtu s využitím q-bit· a kvantového paralelismu pak ve vybraných případech vede k zásadní redukci složitosti. Kvantové počítače potenciálně umožňují realizaci výpočt· a simulací, které jsou s klasickými počíta- či prakticky neproveditelné. Zejména na poli kvantové chemie vyvstává možnost přímočaré aplikace. Tato práce je zaměřena na použití kvantových počítač· pro mnohočásticové problémy a obsahuje analýzu složitosti kvantové simulace atomo- vých jader. Klíčová slova: kvantový počítač, kvantová simulace, mnohočásticová fyzika
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Částicový model pro Higgsův kondensát a anomální geometrická difrakce
Souček, Jiří
In this paper we propose a particle model for the Higgs’ condensate: we propose that this condensate is the set of (infinite velocity) non-local tachyons. We show that then there exists the anomalous geometrical diffraction (which contradicts to quantum mechanics). We show that there exists a universal time constant which defines the limits of the validity of quantum mechanics. We propose an experiment testing the existence of the anomalous geometrical diffraction. We proposed the dark energy conjecture which enables to make an estimate of the time constant. We assume certain (“Feynman”) interaction between standard particle and the nonlocal tachyon. All this is related to the new (finite) form of the Feynman integral.
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Two new uncertainty relations and their applications
Lužová, Martina ; Skála, Lubomír (advisor) ; Kapsa, Vojtěch (referee)
The historical development of uncertainty relation, begining with first Heisenberg's thoughts of uncertainty principle is summed up in this thesis. After proving validity of Schwarz inequality general uncertainty relation for two hermitian operators is obtained, and from this general version the validity of Heisenberg uncertainty relation is than proved. The most important part of this work is the obtention of two new uncertainty relations, which are stronger then Heisenberg or Robertson-Schrödinger uncertainty relation, and their specific form for two examples - a free particle in a state discribed by the gaussian wave packet and the linear harmonic oscillator with a wave function in the shape of gaussian packet.
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Selected Solved Problems in Quantum Mechanics
Fišerová, Kateřina ; Bílek, Oldřich (advisor) ; Žák, Vojtěch (referee)
The main aim of this thesis was to create a set of problems in Quantum Mechanics, which would be included in a collection of solved problems in Physics available online on the website http://www.fyzikalniulohy.cz. As a result, thirty nine problems were completed, covering seven thematic areas partially of high school and mostly of introductory college Quantum Mechanics course. In general, the collection is mainly designed for college students as an exercise in basic quantum-mechanical problems and also for high school students, who have a desire to deal with some special problems. A detailed description of content, structure, and technical execution of this collection can be found in chapter 1 of this thesis. Another task was to review existing online collections of applets dealing with Quantum Mechanics. A selection of them is introduced in chapter 2 of this thesis.
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Hybrid-epistemický model kvantové mechaniky a možné řešení problému měření
Souček, Jiří
In this study we introduce and describe in details the hybrid-epistemic model for quantum mechanics. The main differences with respect to the standard model are following: (1) the measurement process is considered as an internal process inside quantum mechanics, i.e. it does not make a part of axioms and (2) the process of the observation of the state of the individual measuring system is introduced into axioms. The intrinsic measurement process is described in two variants (simplified and generalized). Our model contains hybrid, epistemic and hybrid-epistemic systems. Each hybrid system contains a unique orthogonal base composed from homogeneous (i.e. ontic) states. We show that in our model the measurement problem is consistently solvable. Our model represents the rational compromise between the Bohr’s view (the ontic model) and the Einstein’s view (the epistemic model).
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Obnovení lokality: axiomatická formulace modifikované kvantové mechaniky
Souček, Jiří
From the dichotomy "nonlocality vs non-realism" which is the consequence of Bell Inequalities (BI) we shall choose the non-realism. We shall present here the modified Quantum Mechanics (modQM) in the axiomatic form. ModQM was introduced in [5] and we shall show its non-realism in the description of an internal measurement process. ModQM allows the restoration of locality, since BI cannot be derived in it. In modQM it is possible to solve: the measurement problem, the collapse problem, the problem of a local model for EPR correlations (see[5]). ModQM is a unique explicit realization of non-realism in QM. ModQM should be preferred as an alternative to the standard QM mainly since it restores the locality.
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