2,658,081 research outputs found
Phase Coherence in a Driven Double-Well System
We analyze the dynamics of the molecular field incoherently pumped by the
photoassociation of fermionic atoms and coupled by quantum tunnelling in a
double-well potential. The relative phase distribution of the molecular modes
in each well and their phase coherence are shown to build up owing to quantum
mechanical fluctuations starting from the vacuum state. We identify three
qualitatively different steady-state phase distributions, depending on the
ratio of the molecule-molecule interaction strength to interwell tunnelling,
and examine the crossover from a phase-coherent regime to a phase-incoherent
regime as this ratio increases.Comment: 5 pages, 2 figure
Bifurcations and bistability in cavity assisted photoassociation of Bose-Einstein condensed molecules
We study the photo-association of Bose-Einstein condensed atoms into
molecules using an optical cavity field. The driven cavity field introduces a
new dynamical degree of freedom into the photoassociation process, whose role
in determining the stationary behavior has not previously been considered. The
semiclassical stationary solutions for the atom and molecules as well as the
intracavity field are found and their stability and scaling properties are
determined in terms of experimentally controllable parameters including driving
amplitude of the cavity and the nonlinear interactions between atoms and
molecules. For weak cavity driving, we find a bifurcation in the atom and
molecule number occurs that signals a transition from a stable steady state to
nonlinear Rabi oscillations. For a strongly driven cavity, there exists
bistability in the atom and molecule number
A Molecular Matter-Wave Amplifier
We describe a matter-wave amplifier for vibrational ground state molecules,
which uses a Feshbach resonance to first form quasi-bound molecules starting
from an atomic Bose-Einstein condensate. The quasi-bound molecules are then
driven into their stable vibrational ground state via a two-photon Raman
transition inside an optical cavity. The transition from the quasi-bound state
to the electronically excited state is driven by a classical field.
Amplification of ground state molecules is then achieved by using a strongly
damped cavity mode for the transition from the electronically excited molecules
to the molecular ground state
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Entrepreneurial Literary Theory: A Debate on Research and the Future of Academia
Across the world at present, researchers and teachers are being exhorted to become entrepreneurial. Universities are being restructured accordingly. The debate presented in this book considers what that involves and portends for academia. Literary studies are often regarded as the most resistant to – unfit for – entrepreneurial purposes. Literary research is therefore taken as a baseline for this debate. The uneasy place of literary research within profit-driven academia is revealing of the prevailing conditions for scholarship in all areas.
Questions that are raised and discussed here include: What does doing research for the public good mean? What is the relationship between profits and benefits from research? What are applied and basic research? Are concepts of academic freedom and disinterestedness meaningful? What is the relationship between corporate and academic research? Are skills and knowledge different? Can pursuits like close reading and text interpretation be made profitable? What is literary value and how can it be measured? Can the literary system be modelled to profitable ends? Can university teaching be automatized? What are the differences between a standard publication agreement and a scholarly publication agreement? How can digital and open-access academic publication be made profitable? Does the academic monograph have a future? What sorts of knowledge and skills inform entrepreneurial leadership
Input and output in damped quantum systems III: Formulation of damped systems driven by Fermion fields
A comprehensive input-output theory is developed for Fermionic input fields.
Quantum stochastic differential equations are developed in both the Ito and
Stratonovich forms. The major technical issue is the development of a formalism
which takes account of anticommutation relations between the Fermionic driving
field and those system operators which can change the number of Fermions within
the system
The Lime Content of Rocks of The Upper Cretaceous System of Osborne County, Kansas
This report is the result of several weeks of intensive study and investigation in the field and in the laboratory. In making this study of the rocks of Osborne County, Kansas, the writer is concerned chiefly with the chemistry of the rooks rather than with their geological formation. He has not attempted to make a complete analysis of the rocks, but has limited his investigation in order to determine certain facts concerning their line content. He has attempted to determine the consistency of the percentage of lime in a given member in various parts of the county and also of different beds of a given member in the same locality. He has also investigated the possibility of the existence of limestone of a percentage sufficiently high to be used for cattle feeding and for the manufacture of lime. As far as the writer has been able to determine, there has been no such analysis made for this particular locality previous to this time
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