20 research outputs found
Cold Trapped Ions as Quantum Information Processors
In this tutorial we review physical implementation of quantum computing using
a system of cold trapped ions. We discuss systematically all the aspects for
making the implementation possible. Firstly, we go through the loading and
confining of atomic ions in the linear Paul trap, then we describe the
collective vibrational motion of trapped ions. Further, we discuss interactions
of the ions with a laser beam. We treat the interactions in the travelling-wave
and standing-wave configuration for dipole and quadrupole transitions. We
review different types of laser cooling techniques associated with trapped
ions. We address Doppler cooling, sideband cooling in and beyond the Lamb-Dicke
limit, sympathetic cooling and laser cooling using electromagnetically induced
transparency. After that we discuss the problem of state detection using the
electron shelving method. Then quantum gates are described. We introduce
single-qubit rotations, two-qubit controlled-NOT and multi-qubit controlled-NOT
gates. We also comment on more advanced multi-qubit logic gates. We describe
how quantum logic networks may be used for the synthesis of arbitrary pure
quantum states. Finally, we discuss the speed of quantum gates and we also give
some numerical estimations for them. A discussion of dynamics on off-resonant
transitions associated with a qualitative estimation of the weak coupling
regime and of the Lamb-Dicke regime is included in Appendix.Comment: 44 revtex pages, 23 figures, to appear in Journal of Modern Optic
Dissipation-assisted quantum gates with cold trapped ions
It is shown that a two-qubit phase gate and SWAP operation between ground
states of cold trapped ions can be realised in one step by simultaneously
applying two laser fields. Cooling during gate operations is possible without
perturbing the computation and the scheme does not require a second ion species
for sympathetic cooling. On the contrary, the cooling lasers even stabilise the
desired time evolution of the system. This affords gate operation times of
nearly the same order of magnitude as the inverse coupling constant of the ions
to a common vibrational mode.Comment: 4 pages, 5 figures, substantially revised versio
Multiparticle entanglement with quantum logic networks: Application to cold trapped ions
We show how to construct a multi-qubit control gate on a quantum register of
an arbitrary size N. This gate performs a single-qubit operation on a specific
qubit conditioned by the state of other N-1 qubits. We provide an algorithm how
to build up an array of networks consisting of single-qubit rotations and
multi-qubit control-NOT gates for the synthesis of an arbitrary entangled
quantum state of N qubits. We illustrate the algorithm on a system of cold
trapped ions. This example illuminates the efficiency of the direct
implementation of the multi-qubit CNOT gate compared to its decomposition into
a network of two-qubit CNOT gates.Comment: 13 pages, Revtex4, 10 eps figures, 2 tables, to appear in Phys. Rev.
Effective damping in the Raman cooling of trapped ions
We present a method of treating the interaction of a single three-level ion
with two laser beams. The idea is to apply a unitary transformation such that
the exact transformed Hamiltonian has one of the three levels decoupled for all
values of the detunings. When one takes into account damping, the evolution of
the system is governed by a master equation usually obtained via adiabatic
approximation under the assumption of far-detuned lasers. To go around the
drawbacks of this technique, we use the same unitary transformation to get an
effective master equation.Comment: 15 pages, 5 figures. To appear in Optics Communication
Trends in insurance frauds in 21st century
Tato diplomová práce se zabĂ˝vá problematikou pojistnĂ˝ch podvodĹŻ ve spoleÄŤnosti v 21. stoletĂ. Práce je rozdÄ›lená na teoretickou a praktickou část. V úvodnĂch kapitolách je pojistnĂ˝ podvod vymezenĂ˝ obecnÄ›, vÄŤetnÄ› právnĂ Ăşpravy, moĹľnĂ˝ch pĹ™ĂÄŤin páchánĂ pojistnĂ˝ch podvodĹŻ a samotnĂ©ho dÄ›lenĂ. NáslednÄ› je pozornost vÄ›nována prevenci a rĹŻznĂ˝m metodám a zpĹŻsobĹŻm odhalovánĂ tĂ©to trestnĂ© ÄŤinnosti. Diplomová práce se dále zabĂ˝vá ekonomickĂ˝mi dopady pojistnĂ˝ch podvodĹŻ a vlivem finanÄŤnĂ krize na pojistnĂ˝ trh. CĂlem praktickĂ© části je analyzovat pojistnĂ© podvody v ČeskĂ© republice. SoučástĂ tĂ©to diplomovĂ© práce je takĂ© ekonometrická analĂ˝za, na základÄ› kterĂ© je nasimulována pĹ™edpověď výšky pojistnĂ˝ch podvodĹŻ pro roky 2015 a 2016. ZávÄ›r tĂ©to práce je vÄ›novanĂ˝ interpretaci vĂ˝sledkĹŻ provedenĂ© analĂ˝zy.This master's thesis focuses on insurance frauds in 21st century's society. The thesis is divided into theoretical and practical part. We discuss insurance frauds in general, including jurist regulations, possible reasons to commit insurance frauds and its categorization in the first chapters. Later on we focus on prevention and various detection methods of this criminal activity. Further, the thesis studies economical impacts caused by insurance frauds, and influence of the financial crisis on the insurance market. The goal of the practical section is to analyze insurance frauds in the Czech Republic. Part of the thesis includes simulated prediction of the size of insurance frauds for years 2015 and 2016 based on econometric analysis. The work is concluded by an interpretation of results of the said analysis.Táto diplomová práca sa zaoberá problematikou poistnĂ˝ch podvodov v spoloÄŤnosti v 21. storoÄŤĂ. Práca je rozdelená na teoretickĂş a praktickĂş ÄŤasĹĄ. PriÄŤom v ĂşvodnĂ˝ch kapitolách je poistnĂ˝ podvod vymedzenĂ˝ všeobecne, vrátane právnej Ăşpravy, moĹľnĂ˝ch prĂÄŤin páchania poistnĂ˝ch podvodov a samotnĂ©ho delenia. Následne je pozornosĹĄ venovaná prevencii a rĂ´znym metĂłdam a spĂ´sobom odhaÄľovania tejto trestnej ÄŤinnosti. Diplomová práca sa ÄŹalej zaoberá ekonomickĂ˝mi dopadmi poistnĂ˝ch podvodov a vplyvom finanÄŤnej krĂzy na poistnĂ˝ trh. CieÄľom praktickej ÄŤasti je analyzovaĹĄ poistnĂ© podvody v ÄŚeskej republike. SúčasĹĄou tejto diplomovej práce je aj ekonometrická analĂ˝za na základe ktorej je nasimulovaná predpoveÄŹ výšky poistnĂ˝ch podvodov pre roky 2015 a 2016. Záver práce je venovanĂ˝ interpretácii vĂ˝sledkov danej analĂ˝zy
Financing of regional education in the Slovak Republic during the years 2002 - 2012
CĂlem bakalářskĂ© práce je analyzovat transformaÄŤnĂ zmÄ›ny slovenskĂ©ho regionálnĂho školstvĂ v oblasti financovánĂ v letech 2002 -- 2012, kdy slovenskĂ© školstvĂ procházĂ Ĺ™adou zmÄ›n. Bakalářská práce je ÄŤlenÄ›na do třà kapitol. V prvnĂ kapitole se zaměřuji na teoretickĂ© poznatky v oblasti vzdÄ›lávánĂ a jeho základnĂch priorit. Obsahem kapitoly jsou legislativnĂ zmÄ›ny, kterĂ© nastaly po roce 2002, kdy se pĹ™esouvaly kompetence státnĂch orgánĹŻ na obce a vyššà samosprávnĂ celky. Poukazuji na hlavnĂ zmÄ›ny v oblasti financovánĂ regionálnĂho školstvĂ, kterĂ© se odvĂjely od zákonĹŻ, vyhlášek a naĹ™ĂzenĂ. SystĂ©m financovánĂ analyzuji a porovnávám v druhĂ© kapitole, kterou jsem rozÄŤlenil do dvou obdobĂ. ObdobĂ do roku 2005, kdy jsou školy financovanĂ© normativnÄ› a obdobĂ po roce 2005, kdy se mÄ›nĂ zpĹŻsob financovánĂ nÄ›kterĂ˝ch škol. Všechny teoretickĂ© poznatky z oblasti financovánà školstvĂ aplikuji ve tĹ™etĂ kapitole, která mĹŻĹľe bĂ˝t povaĹľována za praktickou část. Na konkrĂ©tnĂm pĹ™ĂkladÄ› jednotĹ™ĂdnĂ mateĹ™skĂ© školy uvádĂm jednotlivĂ© zdroje financovánĂ. SoučástĂ tĂ©to kapitoly jsou finanÄŤnĂ analĂ˝za pĹ™ĂjmĹŻ a vĂ˝dajĹŻ v ÄŤasovĂ©m rozmezĂ 2002 - 2012 a následná komparace tÄ›chto ĂşdajĹŻ. Pro lepšà porovnánĂ vyuĹľĂvám i grafickĂ© vyjádĹ™enĂ. Všechna zjištÄ›nĂ z oblasti regionálnĂho školstvĂ a konkrĂ©tnÄ› i mateĹ™skĂ© školy uvádĂm v závÄ›ru bakalářskĂ© práce.The Bachelor's thesis deals with an analysis of transformations in Slovak regional education funding in years 2002 -- 2012. During this period the Slovak education was going through many changes. The thesis is divided into three chapters. First chapter focuses on theoretical knowledge of education and its key priorities. This chapter includes legislative changes that occurred after 2002, when the competences moved from state to municipalities and higher local authorities. There are some main changes in the financing of regional schools depending on laws and various regulations. The financing system is analyzed and compared in the second chapter, which is divided into two periods. Until 2005 schools were funded normatively and after 2005 the financing of some schools changed. All theoretical knowledge of education funding is applied in the third chapter, which can be considered as practical one. A one-class nursery school is a particular example of various sources of funding. This chapter includes a financial analysis of incomes and expenditures within the period of 2002 - 2012 and a subsequent comparison of these data. For better comparison there are also used graphical expressions. All findings from the regional education and the nursery school are described in the conclusion of the thesis.CieÄľom mojej bakalárskej práce je analyzovaĹĄ transformaÄŤnĂ© zmeny slovenskĂ©ho regionálneho školstva v oblasti financovania v rokoch 2002 -- 2012, kedy slovenskĂ© školstvo prechádza radou zmien. Bakalárska práca je ÄŤlenená do troch kapitol. V prvej kapitole sa zameriavam na teoretickĂ© poznatky v oblasti vzdelávania a jej základne priority. Obsahom kapitoly sĂş legislatĂvne zmeny, ktorĂ© nastali po roku 2002, kedy sa presĂşvajĂş kompetencie zo štátnych orgánov na obce a vyššie samosprávne celky. Poukazujem na hlavnĂ© zmeny v oblasti financovania regionálneho školstva, ktorĂ© sa odvĂjali od zákonov, vyhlášok a nariadenĂ. SystĂ©m financovania analyzujem a porovnávam v druhej kapitole, ktorĂş som rozÄŤlenil do dvoch obdobĂ. Obdobie do roku 2005, keÄŹ sĂş školy financovanĂ© normatĂvne a obdobie po roku 2005, keÄŹ sa menĂ spĂ´sob financovania niektorĂ˝ch škĂ´l. Všetky teoretickĂ© poznatky z oblasti financovania školstva aplikujem v tretej kapitole, ktorĂş mĂ´Ĺľeme pomenovaĹĄ aj ako praktickĂş. Na konkrĂ©tnom prĂklade jednotriednej materskej školy uvádzam jednotlivĂ© zdroje financovania. SúčasĹĄou tejto kapitoly je finanÄŤná analĂ˝za prĂjmov a vĂ˝davkov v ÄŤasovom rozmedzĂ 2002 -- 2012 a následná komparácia tĂ˝chto Ăşdajov. Pre lepšie porovnanie vyuĹľĂvam aj grafickĂ© vyjadrenie. Všetky zistenia z oblasti regionálneho školstva a konkrĂ©tne aj materskej školy uvádzam v závere bakalárskej práce