25 research outputs found
Efficient and long-lived quantum memory with cold atoms inside a ring cavity
Quantum memories are regarded as one of the fundamental building blocks of
linear-optical quantum computation and long-distance quantum communication. A
long standing goal to realize scalable quantum information processing is to
build a long-lived and efficient quantum memory. There have been significant
efforts distributed towards this goal. However, either efficient but
short-lived or long-lived but inefficient quantum memories have been
demonstrated so far. Here we report a high-performance quantum memory in which
long lifetime and high retrieval efficiency meet for the first time. By placing
a ring cavity around an atomic ensemble, employing a pair of clock states,
creating a long-wavelength spin wave, and arranging the setup in the
gravitational direction, we realize a quantum memory with an intrinsic spin
wave to photon conversion efficiency of 73(2)% together with a storage lifetime
of 3.2(1) ms. This realization provides an essential tool towards scalable
linear-optical quantum information processing.Comment: 6 pages, 4 figure
QUALIDADE DO VINHO PRODUZIDO NO MUNICÍPIO DE COLOMBO NA SAFRA 2001
O presente trabalho faz parte da segunda etapa do Projeto de Extensão No 248/PROEC MELHORIA
DA QUALIDADE DO VINHO PRODUZIDO NO MUNICÍPIO DE COLOMBO, com a finalidade de
acompanhar e avaliar os resultados da implantação de procedimentos de modernização da
tecnologia, identificados como mais adequados durante a realização do curso Elaboração de
Vinhos, ministrado como parte integrante da primeira etapa do projeto. Após o trabalho em
campo, com visitas às diversas vinícolas, foram realizadas análises físico-químicas das diferentes
amostras de vinhos, cujos resultados foram comparados com os padrões fixados pelo Ministério
da Agricultura.
QUALITY OF THE WINE PRODUCED IN COLOMBO CITY IN HARVEST OF 2001
Abstract
The present paper is part of the second phase of the Extension Project nº 248/PROEC IMPROVEMENT
OF QUALITY OF THE WINE PRODUCED IN COLOMBO CITY and shows the results of the implantation of
modern technological wine making procedures on small wineries of Colombo City. On the first
phase of project, themost appropriate techniques were identified during a course on WINE MAKING
presented to winemakers of the region. On the second phase, besides visiting small wineries, physical
and chemical analyses were carried out on several wine samples and the results were compared
with patterns established by the Brazilian Ministry of Agriculture
Evaluation of an efficiency-optimized calculation of PM synchronous machines' operating range using time-saving numerical and analytical coupling
In this paper, a new method for an accurate and also time-saving calculation of permanent magnet synchronous machines is presented. The method is based on a coupled numerical-analytical approach. The aim is to determine efficiency optimized torque-speed characteristics of the drive system. The novel approach considers all kinds of losses, such as switching and conduction losses of the inverter, copper losses, friction losses as well as saturation-dependent hysteresis and eddy current losses of the electrical machine. The presented approach is verified by measurements of a high-torque wheel hub drive