1,335 research outputs found
Discrete Time Quantum Walk Approach to State Transfer
We show that a quantum state transfer, previously studied as a continuous
time process in networks of interacting spins, can be achieved within the model
of discrete time quantum walks with position dependent coin. We argue that due
to additional degrees of freedom, discrete time quantum walks allow to observe
effects which cannot be observed in the corresponding continuous time case.
First, we study a discrete time version of the engineered coupling protocol due
to Christandl et. al. [Phys. Rev. Lett. 92, 187902 (2004)] and then discuss the
general idea of conversion between continuous time quantum walks and discrete
time quantum walks.Comment: 9 pages, 6 figures, comments welcom
Probabilistic coding of quantum states
We discuss properties of probabilistic coding of two qubits to one qutrit and
generalize the scheme to higher dimensions. We show that the protocol
preservers entanglement between qubits to be encoded and environment and can be
also applied to mixed states. We present the protocol which enables encoding of
n qudits to one qudit of dimension smaller than the Hilbert space of the
original system and then probabilistically but error-free decode any subset of
k qudits. We give a formula for the probability of successful decoding
Liquid phase contained in porous rock as observed by proton magnetic relaxation
High power proton relaxometry was applied to investigate the liquid phase contained in porous rock. Proton free induction decays and spin-lattice relaxation times allowed us to investigate the pore distribution and the contribution of mobile and of immobilized liquid. The differences in pore distributions in oil-containing limestone and in Węglowicki sandstone were found. The fractal exponent for pore distribution in Węglowicki sandstone was fitted using both stretched exponential and modified stretched exponential models. The results of both approaches are compared
Numerical Simulations of Torsional Alfv\'en Waves in Axisymmetric Solar Magnetic Flux Tubes
We investigate numerically Alfv\'en waves propagating along an axisymmetric
and non-isothermal solar flux tube embedded in the solar atmosphere. The tube
magnetic field is current-free and diverges with height, and the waves are
excited by a periodic driver along the tube magnetic field lines. The main
results are that the two wave variables, the velocity and magnetic field
perturbations in the azimuthal direction, behave differently as a result of
gradients of physical parameters along the tube. To explain these differences
in the wave behavior, the time evolution of the wave variables and the
resulting cutoff period for each wave variable are calculated, and used to
determine regions in the solar chromosphere where strong wave reflection may
occur.Comment: Submitted to Solar Physics (accepted
WORLD ECONOMIC RECESSION VS. LABOUR MARKET GLOBALIZATION
Стаття присвячена оцінці впливу глобалізації і світової кризи на розвиток польської економіки. Визначено тенденції розвитку ринку праці в країнах Європейської спільноти. Проаналізовано роль держави у регулюванні процесів економічної взаємодії. Розглянуто моделі глобалізації на основі утворення регіональних об’єднань. Запропоновано рекомендації для адаптації польського ринку праці до нових економічних умов.The paper is dealt with evaluation of labour market globalization and global economic recession impacts on Polish economic growth. Trends of labour market changes in EU countries are determined. The role of the government in regulation of economic interactions processes is analyzed. The paper also considers models of globalization on the basis of developing regional systems. Some guidelines are proposed to adapt Polish labour market to new economic conditions
EWOLUCJA MODELU SYMULACYJNEGO SYSTEMU SAMOREGULACJI NAPRĘŻENIA TAŚMY W TRYBIE DYNAMICZNYM W LINII CIĄGŁEGO CYNKOWANIA NA GORĄCO
The paper deals with the peculiarities of development of simulation model of strip pull self-regulation system in a continuous hot galvanizing line. The results of simulation modelling are provided.W artykule rozpatrzono cechy szczególne konstruowania modelu symulacyjnego systemu regulacji naprężenia taśmy w linii ciągłej cynkowania na gorąco. Przedstawiono wyniki badań symulacyjnych
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