13,612 research outputs found
On the role of coupling in mode selective excitation using ultrafast pulse shaping in stimulated Raman spectroscopy
The coherence of two, coupled two-level systems, representing vibrational
modes in a semiclassical model, is calculated in weak and strong fields for
various coupling schemes and for different relative phases between initial
state amplitudes. A relative phase equal to projects the system into a
dark state. The selective excitation of one of the two, two-level systems is
studied as a function of coupling strength and initial phases.Comment: 7 pages, 4 figure
Direct comparison of Viking 2.3-GHz signal phase fluctuation and columnar electron density between 2 and 160 solar radii
The relationship between solar wind induced signal phase fluctuation and solar wind columnar electron density has been the subject of intensive analysis during the last two decades. In this article, a sizeable volume of 2.3-GHz signal phase fluctuation and columnar electron density measurements separately and concurrently inferred from Viking spacecraft signals are compared as a function of solar geometry. These data demonstrate that signal phase fluctuation and columnar electron density are proportional over a very wide span of solar elongation angle. A radially dependent electron density model which provides a good fit to the columnar electron density measurements and, when appropriately scaled, to the signal phase fluctuation measurements, is given. This model is also in good agreement with K-coronameter observations at 2 solar radii (2r0), with pulsar time delay measurements at 10r0, and with spacecraft in situ electron density measurements at 1 AU
Cigar manufacturing costs
In discussing the various phases of the Tobacco and the Cigar Manufacturing industries a brief outline will be made of a number of factors which must be known in order to understand the cost accounting procedure. Language : en
General-Purpose Parallel Simulator for Quantum Computing
With current technologies, it seems to be very difficult to implement quantum
computers with many qubits. It is therefore of importance to simulate quantum
algorithms and circuits on the existing computers. However, for a large-size
problem, the simulation often requires more computational power than is
available from sequential processing. Therefore, the simulation methods using
parallel processing are required.
We have developed a general-purpose simulator for quantum computing on the
parallel computer (Sun, Enterprise4500). It can deal with up-to 30 qubits. We
have performed Shor's factorization and Grover's database search by using the
simulator, and we analyzed robustness of the corresponding quantum circuits in
the presence of decoherence and operational errors. The corresponding results,
statistics and analyses are presented.Comment: 15 pages, 15 figure
Women and Monasticism in Medieval Europe: Sisters and Patrons of the Cistercian Reform
A selection of documents, translated primarily from medieval Latin but occasionally from Old French, that shows how religious women and their patrons managed resources to make monastic communities - particularly a variety of Cistercian communities - work. The records help us reconstruct how nuns and abbesses of Cistercian communities in the thirteenth century organized and kept records, managed their properties, responded to attempts at usurpation, and balanced their lives between devotional practices, which were part of their cloistered world, and family and social responsibilities beyond the convent walls.https://scholarworks.wmich.edu/mip_teamsdp/1003/thumbnail.jp
Gaussian approximation and single-spin measurement in OSCAR MRFM with spin noise
A promising technique for measuring single electron spins is magnetic
resonance force microscopy (MRFM), in which a microcantilever with a permanent
magnetic tip is resonantly driven by a single oscillating spin. If the quality
factor of the cantilever is high enough, this signal will be amplified over
time to the point that it can be detected by optical or other techniques. An
important requirement, however, is that this measurement process occur on a
time scale short compared to any noise which disturbs the orientation of the
measured spin. We describe a model of spin noise for the MRFM system, and show
how this noise is transformed to become time-dependent in going to the usual
rotating frame. We simplify the description of the cantilever-spin system by
approximating the cantilever wavefunction as a Gaussian wavepacket, and show
that the resulting approximation closely matches the full quantum behavior. We
then examine the problem of detecting the signal for a cantilever with thermal
noise and spin with spin noise, deriving a condition for this to be a useful
measurement.Comment: 12 pages, 8 figures in EPS format, RevTeX 4.
The photon blockade effect in optomechanical systems
We analyze the photon statistics of a weakly driven optomechanical system and
discuss the effect of photon blockade under single photon strong coupling
conditions. We present an intuitive interpretation of this effect in terms of
displaced oscillator states and derive analytic expressions for the cavity
excitation spectrum and the two photon correlation function . Our
results predict the appearance of non-classical photon correlations in the
combined strong coupling and sideband resolved regime, and provide a first
detailed understanding of photon-photon interactions in strong coupling
optomechanics
Dynamical Stability and Quantum Chaos of Ions in a Linear Trap
The realization of a paradigm chaotic system, namely the harmonically driven
oscillator, in the quantum domain using cold trapped ions driven by lasers is
theoretically investigated. The simplest characteristics of regular and chaotic
dynamics are calculated. The possibilities of experimental realization are
discussed.Comment: 24 pages, 17 figures, submitted to Phys. Rev
Quantum Measurement of a Single Spin using Magnetic Resonance Force Microscopy
Single-spin detection is one of the important challenges facing the
development of several new technologies, e.g. single-spin transistors and
solid-state quantum computation. Magnetic resonance force microscopy with a
cyclic adiabatic inversion, which utilizes a cantilever oscillations driven by
a single spin, is a promising technique to solve this problem. We have studied
the quantum dynamics of a single spin interacting with a quasiclassical
cantilever. It was found that in a similar fashion to the Stern-Gerlach
interferometer the quantum dynamics generates a quantum superposition of two
quasiclassical trajectories of the cantilever which are related to the two spin
projections on the direction of the effective magnetic field in the rotating
reference frame. Our results show that quantum jumps will not prevent a
single-spin measurement if the coupling between the cantilever vibrations and
the spin is small in comparison with the amplitude of the radio-frequency
external field.Comment: 16 pages RevTeX including 4 figure
Single-atom laser generates nonlinear coherent states
The stationary state of a single-atom (single-qubit) laser is shown to be a
phase-averaged nonlinear coherent state - an eigenstate of a specific deformed
annihilation operator. The solution found for the stationary state is unique
and valid for all regimes of the single-qubit laser operation. We have found
the parametrization of the deformed annihilation operator which provides
superconvergence in finding the stationary state by iteration. It is also shown
that, contrary to the case of the usual laser with constant Einstein
coefficients describing transition probabilities, for the single-atom laser the
interaction-induced transition probabilities effectively depend on the field
intensity
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