27 research outputs found
Spatial Coherence of a Polariton Condensate
We perform Young's double-slit experiment to study the spatial coherence
properties of a two-dimensional dynamic condensate of semiconductor microcavity
polaritons. The coherence length of the system is measured as a function of the
pump rate, which confirms a spontaneous buildup of macroscopic coherence in the
condensed phase. An independent measurement reveals that the position and
momentum uncertainty product of the condensate is close to the Heisenberg
limit. An experimental realization of such a minimum uncertainty wave packet of
the polariton condensate opens a door to coherent matter-wave phenomena such as
Josephson oscillation, superfluidity, and solitons in solid state condensate
systems
Quantum Degenerate Exciton-Polaritons in Thermal Equilibrium
We study the momentum distribution and relaxation dynamics of semiconductor
microcavity polaritons by angle-resolved and time-resolved spectroscopy. Above
a critical pump level, the thermalization time of polaritons at positive
detunings becomes shorter than their lifetime, and the polaritons form a
quantum degenerate Bose-Einstein distribution in thermal equilibrium with the
lattice.Comment: Updated with the published versio
Информационная система учёта и анализа услуг ветеринарной клиники ООО "ТАМАСИНА".
Объектом исследования является деятельность ООО "ТАМАСИНА" по оказанию ветеринарных услуг населению нашему городу. Цель работы – проектирование информационной система учёта и анализа услуг ветеринарной клиники ООО "ТАМАСИНА". В процессе исследования проводился теоретический анализ, обзор аналогов, проектирование и разработка информационной системы. В результате разработана информационная система, реализующая основные функции: учет клиентов клиники; учет оказанных услуг; учет расхода лекарственных препаратов; анализ оказания услуг. Область применения: оказание ветеринарных услуг, реклама, учет клиентов ветеринарной клиники, информирование населения о деятельности организации, осуществление обратной связи с клиентами.The object of the study is the activity of LLC "TAMASINA" in providing veterinary services to the population of our city. The purpose of the work is the design of the information system for accounting and analysis of the services of the veterinary clinic of LLC "TAMASINA". In the process of the research, a theoretical analysis, a review of analogues, design and development of an information system were carried out. As a result, the educational system that implements the main functions: the account of the clients of the clinic; Accounting services provided; Accounting for medicines soon; Analysis of the provision of services. Scope: the provision of veterinary services, advertising, accounting of customers of veterinary clinics
Mesoscopic spin confinement during acoustically induced transport
Long coherence lifetimes of electron spins transported using moving potential
dots are shown to result from the mesoscopic confinement of the spin vector.
The confinement dimensions required for spin control are governed by the
characteristic spin-orbit length of the electron spins, which must be larger
than the dimensions of the dot potential. We show that the coherence lifetime
of the electron spins is independent of the local carrier densities within each
potential dot and that the precession frequency, which is determined by the
Dresselhaus contribution to the spin-orbit coupling, can be modified by varying
the sample dimensions resulting in predictable changes in the spin-orbit length
and, consequently, in the spin coherence lifetime.Comment: 10 pages, 2 figure
Magneto-transport in periodic and quasiperiodic arrays of mesoscopic rings
We study theoretically the transmission properties of serially connected
mesoscopic rings threaded by a magnetic flux. Within a tight-binding formalism
we derive exact analytical results for the transmission through periodic and
quasiperiodic Fibonacci arrays of rings of two different sizes. The role played
by the number of scatterers in each arm of the ring is analyzed in some detail.
The behavior of the transmission coefficient at a particular value of the
energy of the incident electron is studied as a function of the magnetic flux
(and vice versa) for both the periodic and quasiperiodic arrays of rings having
different number of atoms in the arms. We find interesting resonance properties
at specific values of the flux, as well as a power-law decay in the
transmission coefficient as the number of rings increases, when the magnetic
field is switched off. For the quasiperiodic Fibonacci sequence we discuss
various features of the transmission characteristics as functions of energy and
flux, including one special case where, at a special value of the energy and in
the absence of any magnetic field, the transmittivity changes periodically as a
function of the system size.Comment: 9 pages with 7 .eps figures included, submitted to PR
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Erforschung eines diodengepumpten (Multi-core) M-Profil-Faserlasers im Ultrakurzpulsbetrieb, Unterauftrag: Entwicklung eines Halbleiter-Bauelementes aus Bragg-Reflektoren, sättigbarem Absorber und 2-Photonen-Absorber : Abschlußbericht über das F&E-Vorhaben
[no abstract available
Unrechtsurteile der NS-Zeit
Kempny S. Unrechtsurteile der NS-Zeit. In: Drüen K-D, Hey J, Mellinghoff R, eds. 100 Jahre Steuerrechtsprechung in Deutschland. Festschrift für den Bundesfinanzhof. Vol 1. Köln: Dr. Otto Schmidt; 2018: 39-58
Ultrafast Nonlinear Terahertz Studies of High-Field Charge Transport in Semiconductors
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