Speeding up antidynamical Casimir effect with nonstationary qutrits

The antidynamical Casimir effect (ADCE) is a term coined to designate the coherent annihilation of excitations due to resonant external perturbation of system parameters, allowing for extraction of quantum work from nonvacuum states of some field. Originally proposed for a two-level atom (qubit) coupled to a single cavity mode in the context of nonstationary quantum Rabi model, it suffered from very low transition rate and correspondingly narrow resonance linewidth. In this paper we show analytically and numerically that the ADCE rate can be increased by at least one order of magnitude by replacing the qubit by an artificial three-level atom (qutrit) in a properly chosen configuration. For the cavity thermal state we demonstrate that the dynamics of the average photon number and atomic excitation is completely different from the qubit's case, while the behavior of the total number of excitations is qualitatively similar yet significantly faster.Comment: 9 pages, 4 figure

Effect of current corrugations on the stability of the tearing mode

The generation of zonal magnetic fields in laboratory fusion plasmas is predicted by theoretical and numerical models and was recently observed experimentally. It is shown that the modification of the current density gradient associated with such corrugations can significantly affect the stability of the tearing mode. A simple scaling law is derived that predicts the impact of small stationary current corrugations on the stability parameter $\Delta'$. The described destabilization mechanism can provide an explanation for the trigger of the Neoclassical Tearing Mode (NTM) in plasmas without significant MHD activity.Comment: Accepted to Physics of Plasma

Coupled structural, thermal, phase-change and electromagnetic analysis for superconductors, volume 1

This research program has dealt with the theoretical development and computer implementation of reliable and efficient methods for the analysis of coupled mechanical problems that involve the interaction of mechanical, thermal, phase-change and electromagnetic subproblems. The focus application has been the modeling of superconductivity and associated quantum-state phase-change phenomena. In support of this objective the work has addressed the following issues: (1) development of variational principles for finite elements; (2) finite element modeling of the electromagnetic problem; (3) coupling of thermal and mechanical effects; and (4) computer implementation and solution of the superconductivity transition problem. The research was carried out over the period September 1988 through March 1993. The main accomplishments have been: (1) the development of the theory of parametrized and gauged variational principles; (2) the application of those principled to the construction of electromagnetic, thermal and mechanical finite elements; and (3) the coupling of electromagnetic finite elements with thermal and superconducting effects; and (4) the first detailed finite element simulations of bulk superconductors, in particular the Meissner effect and the nature of the normal conducting boundary layer. The grant has fully supported the thesis work of one doctoral student (James Schuler, who started on January 1989 and completed on January 1993), and partly supported another thesis (Carmelo Militello, who started graduate work on January 1988 completing on August 1991). Twenty-three publications have acknowledged full or part support from this grant, with 16 having appeared in archival journals and 3 in edited books or proceedings

Coupled structural, thermal, phase-change and electromagnetic analysis for superconductors, volume 2

Two families of parametrized mixed variational principles for linear electromagnetodynamics are constructed. The first family is applicable when the current density distribution is known a priori. Its six independent fields are magnetic intensity and flux density, magnetic potential, electric intensity and flux density and electric potential. Through appropriate specialization of parameters the first principle reduces to more conventional principles proposed in the literature. The second family is appropriate when the current density distribution and a conjugate Lagrange multiplier field are adjoined, giving a total of eight independently varied fields. In this case it is shown that a conventional variational principle exists only in the time-independent (static) case. Several static functionals with reduced number of varied fields are presented. The application of one of these principles to construct finite elements with current prediction capabilities is illustrated with a numerical example

Knowing What Matters: An Expanded Study of School Bond Elections in Michigan, 1998-2006

This study investigates what factors are associated with the likelihood of passing school facility construction bonds by local district election. It uses statewide data from Michigan, 1998–2006, to examine the outcome of 789 bond elections in terms of ten variables: amount of the bond request; district enrollment; district locale; percentage of students receiving free school lunches; percentage of the district population with only a high school degree; the district’s long-term debt; voter turnout; the day of the calendar year on which the election is held; the number of the bond proposal on the ballot; and the inclusion of technology in the ballot proposal’s wording. The logistic regression analysis finds that bond amount, percentage of students receiving free lunches, percentage of district population with only a high school degree, voter turnout, and being further down on the ballot are all negative and significant factors. District long-term debt and holding the election later in the calendar year are both positive and significant factors. District enrollment numbers are non-significant. In terms of district locale (using mid-sized city/suburban districts as the reference group), being a small town and rural district is a negative and significant factor

From the maternal to the mechanical: the struggle against sentiment in contemporary American motherhood poetry

The purpose of this study is to examine the poems of a small number of contemporary American poets who have worked to undermine poetic traditions of sentimentality that have sometimes figured large in the representation of motherhood. The study focuses on writers who have been formative to my own practice and who have helped me consider a challenge that I have wrestled with in my own writing and personal life. I write about their practices in relation to my own creative project, and to a concern that the more challenging aspects of motherhood not be oppressed. The first two chapters define idealism and sentimentality as factors that have been an important strand of motherhood poetry, explore the ways in which some contemporary American poets have sought to counter these factors in their work, and address the ways in which poets such as Sylvia Plath have examined the loss of maternal identity, which acts as precursor to the depersonalization of the mother in poetry. The thesis then investigates the depersonalization of the maternal figure by addressing the ways in which the mother can be mechanized and objectified in poems, and explores the objectification of the child in the work of several poets, showing how children have been embodied as objects in order to counter the culturally enforced response a child’s presence engenders. These later chapters also explore some of the reasons a poet might objectify the mother and child figure, and address the effects of this approach. As a way of concluding each chapter, the study speaks to the creative manuscript and its contextualization, discussing the ways in which the research has influenced the writing of the poems. The creative portion of the work is a manuscript of poems titled 'The Reproduction Cinema', which also addresses maternal struggle. The study finds that the objectification and depersonalization of mother and child is one important method by which poets wishing to write against more traditional ideas of motherhood might do so. The conclusion suggests that this more inclusive version of a poetics of the maternal experience will help broaden the discourse around the poetry of motherhood

Population trapping due to cavity losses

In population trapping the occupation of a decaying quantum level keeps a constant non-zero value. We show that an atom-cavity system interacting with an environment characterized by a non-flat spectrum, in the non-Markovian limit, exhibits such a behavior, effectively realizing the preservation of nonclassical states against dissipation. Our results allow to understand the role of cavity losses in hybrid solid state systems and pave the way to the proper description of leakage in the recently developed cavity quantum electrodynamic systems.Comment: 4 pages, 3 figures, version accepted for publication on Phys. Rev.

Characterisation of the L-mode Scrape Off Layer in MAST: decay lengths

This work presents a detailed characterisation of the MAST Scrape Off Layer in L-mode. Scans in line averaged density, plasma current and toroidal magnetic field were performed. A comprehensive and integrated study of the SOL was allowed by the use of a wide range of diagnostics. In agreement with previous results, an increase of the line averaged density induced a broadening of the midplane density profile.Comment: 30 pages, 11 figure