Negotiating the state: National utopias and local politics in Andean Ecuador, 1845--1875 (Gabriel Garcia Moreno)

Williams, Derek State University of New York at Stony Brook 2001 해외박사(DDOD)

This dissertation studies political struggles over the formation of state-society boundaries and national community in Ecuador between 1845 and 1875. It examines two state-led national initiatives—the “popular liberal experiment” of the 1850s and, more centrally, the “modern Catholic” program of the Gabriel Garcia Moreno government (1861–1875). It considers these development projects as attempts to infuse local cultures and politics with state-centered understandings about “progress” and “nation.” In part it studies the imaginings (or utopias) of state elites—and the “official” discourses they produced. It also examines the institutions and mechanisms through which the government sought to establish national standards over local. In so doing, it assesses how state initiatives of both popular liberalism and Catholic nationalism were engaged by, negotiated, and reshaped by local political actors in the Ecuadorian highlands. The centerpiece of this dissertation is Garcia Moreno government's efforts to construct an ultra-Catholic Ecuadorian nation. Specifically, it examines state strategies to inculcate ultra-Catholic piety and morality as the sole basis for the national collective identity. In seeking to forge a <italic> pueblo católico</italic>, the Garcian government was committed to imposing an austere and repressive—yet also practical and progressive—Catholic morality on all classes, all ethnic groups and both men and women. It established a national primary school system, and promoted religiosity and virtue through the vigorous policing of profane and scandalous custom. Particularly after 1869, the central government forcefully pursued a politics of moralization that focused on the promotion of worship, the eradication of drinking, the extirpation of pagan festivities and the regulation of sexuality. This study examines the particular gender and racial dimensions of state discourse and policy, revealing the central importance of both women and indígenas to the construction of a Catholic national identity. It also argues that the regulation and reform of individual behavior sought to incorporate and discipline both subaltern non-citizens and white-male citizens within a “truly Catholic nation.&rdquo. As a study of state formation, it examines the strategies and mechanisms by which the Garcian government sought to implement and administer a nationally conceived <italic>pueblo católico</italic>. Specifically, it examines the process by which the central government sought to coordinate the institutions of the Church, municipal government, hacienda, and Indian community, and to redeploy them to work for “national” ends—such as road building, rural schooling, and moralizing campaigns. It explores the achievements and limits of this model for strengthening state power and disseminating state-centered meanings of Catholic community and progress. It contends that the most impressive accomplishment of the Garcia-era government was to establish religiosity and morality as the central notions through which social and political claims could be “legitimately” framed.

Polaronic effects in manganese oxides: Self-trapped electronic states in lanthanum manganate and sodium chloride

Perebeinos, Vasili State University of New York at Stony Brook 2001 해외박사(DDOD)

Self-trapped states occur in many insulating solids but are not especially well-understood. There is a need for better theoretical models and better experimental tools for exploring these states. This thesis provides models for two kinds of materials LaMnO₃ and NaCl, and predicts experimental effects which can be used to characterize such states. LaMnO₃ is an insulating antiferromagnet which can be doped with holes over a wide concentration range, as in La₁₋<italic>_x</italic>Ca<italic>_x</italic>MnO₃. Here I study the regime <italic>x</italic> <math> <f> ≪</f> </math> 1 where particularly interesting and simple behavior is predicted. The model has electronic and lattice-vibrational degrees of freedom chosen to represent the Mn ion outer electronic states and their interaction with oxygen motions in the three dimensional perovskite crystal structure. Four independent types of data are available to choose three adjusted parameters. Using electronic structure calculations, optical conductivity and Raman spectra for this choice the predicted magnitude of the static Jahn-Teller distortion agrees within 10–15% with neutron diffraction data. I use the model to analyze and predict the self-localized states which form under optical excitation and under hole doping. In particular five types of behavior are analyzed: (1) the insulating nature of lightly doped LaMnO₃ due to the anti-Jahn-Teller polaron formation; (2) phonon broadening due to the exciton formation; (3) polaronic angle-resolved-photoemission-spectra (ARPES); (4) Raman spectra due to the Franck-Condon mechanism; (5) the self-trapped exciton in NaCl and its optical properties including the Franck-Condon effect using the first-principles Density Functional Theory (DFT) calculations. Experimental confirmation of the predicted behavior for LaMnO₃ will differentiate the Jahn-Teller model studied here from competing versions. The results given here are novel in five ways. (1) Essentially exact analytical polaronic spectra of the two-orbital model Hamiltonian have been obtained. (2) Self-trapped exciton solution explains the broadening of the optical spectra. (3) <bold>k</bold>-dependent peak position and broadening of the ARPES spectra are predicted. (4) Resonant multiphonon Raman spectra were predicted and subsequently observed. (5) DFT first-principles calculations are used for the first time to study a self-trapped state in a real material, namely the self-trapped exciton in NaCl.

Atom optics with Rydberg states in inhomogeneous electric fields

Kritsun, Oleg Anton State University of New York at Stony Brook 2003 해외박사(DDOD)

Atom optics has become subject of intense investigation in recent years. Control of atomic motion is of great importance in atomic physics and applications like lithography or nanofabrication. Neutral atoms are not affected greatly by magnetic or electric field as they don't have a charge or large magnetic and electric moments. But by exciting a neutral atom to a high Rydberg state it is possible to increase its electric moment considerably. The purpose of this thesis is to demonstrate experimentally and theoretically the possibility of creating atom optical elements for the beam of neutral atoms based on the polarizability of highly excited states in an electric field. First this work will present a review of the basic concepts that are used for atom optics and also a discussion of the progress to date in realizations of the neutral atom manipulation techniques. In our earlier experiments deflection and beam-splitting was demonstrated for a beam of neutral Lithium atoms excited in a three-step scheme [3.5, 3.6]. In later experiments, metastable Helium was excited from 23S state to the 33P state using lambda = 389 nm light, and then to the 25--30 S or D states using lambda = 785--815 nm light. Because this was a two-step excitation and it had the higher laser power in the last step, this method increased the percentage of excited atoms by a factor close to 103 compared to the Lithium experiment. Furthermore coherent excitation technique, Stimulated Raman Adiabatic Population Transfer (STIRAP), is investigated in this system, which allows a complete transfer of the atoms from 23S to the Rydberg states. STIRAP is also very tolerant of experimental imperfections such as intensity and frequency fluctuations, Doppler shifts, etc. and can be done with modest laser power. Efficient excitation enables us to do the following atom manipulations in inhomogeneous electric field [3.6, 4.42]. (1) Deflection and reflection; (2) Beam-splitting; (3) Collimation and focusing. Since this field is relatively new there is still a great deal to be learned, and many of the experimental techniques discussed as well as the research that was done represent the earliest work in this field. As research continues, it is likely that more innovations will be forthcoming, and the full potential of the technique will be realized.

Excitation of Helium to Rydberg States Using STIRAP

Lu, Xiaoxu State University of New York at Stony Brook 2011 해외박사(DDOD)

Driving atoms from an initial to a final state of the same parity via an intermediate state of opposite parity is most efficiently done using STIRAP, because it does not populate the intermediate state. For optical transitions this requires appropriate pulses of light in the counter-intuitive order - first coupling the intermediate and final states. We populate Rydberg states of helium (n = 12 ∼ 30) in a beam of average velocity 1070 m/s by having the atoms cross two laser beams in a tunable dc electric field. The "red" light near lambda = 790 ~ 830 nm connects the 33P states to the Rydberg states and the "blue" beam of lambda = 389 nm connects the metastable 2 3S state atoms emitted by our source to the 33 P states. By varying the relative position of these beams we can vary both the order and the overlap encountered by the atoms. We vary either the dc electric field and fix the " red " laser frequency or vary the "red" laser frequency and fix the dc electric field to sweep across Stark states of the Rydberg manifolds. Several mm downstream of the interaction region we apply the very strong bichromatic force on the 23S → 2 3P transition at lambda = 1083 nm. It deflects the remaining 23S atoms out of the beam and the ratio of this signal measured with STIRAP beam on and off provides an absolute measure of the fraction of the atoms remaining in the 23 S state. Simple three-level models of STIRAP all predict 100% excitation probability, but our raw measurements are typically around half of this, and vary with both n and l of the Rydberg states selected for excitation by the laser frequency and electric field tuning on our Stark maps. For states with high enough Rabi frequency, after correction for the decay back to the metastable state before the deflection, the highest efficiencies are around 70%. An ion detector readily detects the presence of Rydberg atoms. We believe that the observed signals are produced by black-body ionization at a very low rate, but sufficient to ionize about 0.5 ∼ 1.0 % of the atoms in a region viewed by our detector. Many measurements provide support for this hypothesis.

Phase separation and neighboring ground states of superconductivity in KxFe2---ySe 2

Ryu, Hyejin State University of New York at Stony Brook 2014 해외박사(DDOD)

Iron-based superconductor KxFe2-ySe 2 has generated considerable attention having higher critical temperature (~31 K)* than previously reported FeSe series (~8 K) and showing a unique phase separation with Fe vacancy order. We investigate the effect of the chemical substitution to the ground state and report various ground states such as spin glass phase and superconductor-insulator transition (SIT) under high-magnetic field by substitution of Na, Te, and Ni on KxFe2-ySe 2 single crystal. The normal-state in-plane resistivity below Tc and the upper critical field for KxFe2-ySe1.85Te0.15 and K0.50Na0.24Fe2-ySe2 are measured by suppressing superconductivity in pulsed magnetic fields. The normal-state resistivity is found to increase logarithmically as T/T c goes to 0 with decreasing temperature similar to granular superconductors and Cu-based high-Tc superconductors. Our results suggest that SIT may be induced in high magnetic fields, which is related to the intrinsic real space phase separated states. We also present a ground state change of KxFe2-delta-yNiySe2 (0.06≤y≤1.44) single crystal alloys. Small amount of Ni (~ 4%) substitution suppresses superconductivity below 1.8 K and for higher Ni content insulating spin glass magnetic ground state is induced.

Strong field control of multilevel quantum systems

Clow, Stephen Daniel State University of New York at Stony Brook 2010 해외박사(DDOD)

In this thesis, we present work on coherent control of multilevel quantum systems in the strong field limit using shaped ultrafast laser pulses. In recent years there have been numerous multiphoton absorption experiments in two, three, and four-level atomic/molecular systems and many are performed in the limit of weak fields where perturbation theory is valid. Here, we describe a series of experiments aimed at exploring and understanding multiphoton transitions when the exciting field is strong and perturbation theory breaks down. Our approach to strong field control utilizes both parameterized scans of various pulse shapes and closed-loop learning control to identify a pulse shape that is optimal for populating a target quantum state. With this we will highlight the difference between sequential population transfer and adiabatic rapid passage in multilevel systems with multiphoton coupling between levels. Additionally, we examine strong field control of a four-level atomic interferometer and show how interference in a target state changes from resonant pathways in the frequency domain to time-domain interference via a singe path. Further, we use shaped femtosecond pulses to demonstrate a phenomenon in which a three-level atom becomes a modulator of an ultrafast pulse. The results are based on a pump-probe scheme that is very similar to Electromagnetically Induced Transparency (EIT). Important dynamics associated with a time-dependent coupling field are examined. Lastly, we extend previous work on two-photon driven superfluorescence from a shaped ultrafast drive laser and show how stimulated emission near threshold can turn modest coherent control yields into essentially perfect discrimination between systems where a control factor of about 104 is achieved between atomic and molecular species.

Design and Analysis of Parallel Algorithms for Multiscale Modeling of Platelets

Zhang, Na State University of New York at Stony Brook 2015 해외박사(DDOD)

This work presents multiscale models and efficient numerical algorithms for analyzing the activation mechanisms of platelets under blood flow conditions at disparate spatiotemporal scales on supercomputers, with applications in initial thrombogenicity study and medical device optimization. Modeling the multiscale structures of platelets and the dynamics of their motion in viscous blood plasma require multiple time stepping (MTS) algorithm to optimally utilize the computing resources. This MTS algorithm improves the computational efficiency while maintaining stability and prescribed precisions. Our study of the dynamic properties of flipping platelets adapts the hybridized dissipative particle dynamics and coarse-grained molecular dynamics methods, which resolve the appropriate spatial scales of the platelet and the blood flow, respectively. In addition to the algorithmic strategies, general-purpose graphics processing units are also introduced to speed up the computationally intensive force field evaluations. Examinations of the implementation of the double-punch speedup strategy, i.e., algorithmic MTS and hardware acceleration, reveal significant speedups over single time stepping algorithms and CPU-only solutions. Detailed performance analysis on three representative supercomputers affords the possibility of simulating the millisecond-scale hematology at resolutions of nanoscale platelet and mesoscale bio-flow using millions of particles, the state-of-the-art for the field at the present time.

A Search for First Generation Leptoquarks in Center of Mass Energy = 7 TeV Proton-Proton Collisions with the ATLAS Detector

Stupak, John, III State University of New York at Stony Brook 2012 해외박사(DDOD)

The Standard Model is an incomplete theory of nature. Numerous extensions of the Standard Model predict the existence of leptoquarks (LQ), color-triplet bosons which carry both baryon and lepton number. This dissertation presents the results of a search for pair production of first generation scalar leptoquarks in the eMETjj final state. The search is performed in pp collisions corresponding to an integrated luminosity of 1.03 fb-1, at a center-of-mass energy s = 7 TeV, recorded with the ATLAS detector at the LHC. A multivariate discriminant is used to distinguish signal-like events from background-like events. Observations are consistent with expectations from Standard Model backgrounds, thus limits on allowed LQ mass are determined. First generation scalar leptoquarks with mass mLQ < 558 GeV are excluded at a 95% confidence level for beta ≡ BR( LQ → eq) = 0.5. When combined with a complimentary search in the eejj final state, leptoquarks with mass mLQ < 607 (660) GeV are excluded for beta = 0.5 (1.0). These are the strongest limits in existence.

Advances in the quantitative analysis of public policy

Buckley, Sean Patrick State University of New York at Stony Brook 2003 해외박사(DDOD)

This dissertation is a collection of four papers with a common theme: the improvement of the quantitative empirical analysis of public policy, particularly as it is practiced by political scientists. The first paper reviews the application of discrete event history estimators to the empirical testing of theories about the diffusion of public policy and makes several suggestions for improving these methods, using data on the diffusion of state lotteries. The second paper discusses the application of the dynamic linear model, a variant of Bayesian time series analysis that allows simultaneous estimation of varying coefficients in the state-space as well. This technique is illustrated with a substantive example estimating the time-varying effect of conservative think-tanks on public opinion about regulatory policy. The third paper reviews the method of propensity score matching as a means of accounting for self-selection bias in observational evaluation studies, and suggests a novel method of retaining the advantages of propensity score matching while estimating more complex models than usually seen in the propensity score literature. The specific evaluation question involves the satisfaction of parents with their children's schools, and the models are illustrated with original survey data. The final paper presents an application of both Bayesian hierarchical modeling and the new Compound Hierarchical Ordered Probit estimator to detect differential item functioning in the responses of parents to questions rating their children's schools on a variety of measures, again using original survey data.

Theory of two perovskite solid state systems

Chen, Yiing-Rei State University of New York at Stony Brook 2003 해외박사(DDOD)

This thesis has two major parts. The first part reports studies on CaMnO 3. The ground state of a single doped-in electron in this system is investigated using a tight-binding model Hamiltonian. The model describes the interplay among core spin antiferromagnetic exchange, double exchange, and electron-phonon interaction. A spin-lattice polaron state is found to be favored over a delocalized state. The optical conductivity spectrum of such a polaron is calculated with a non-adiabatic treatment of the lattice degrees of freedom. The second part of this thesis focuses on a density functional calculation of bulk alpha-AlF3, using pseudopotential and local density approximation methods. The aim is to look at the cause of the structural phase transition of alpha-AlF3. The zero temperature energy surface is examined by these methods, and is used to obtain properties including structural parameters, density of states, dielectric functions, soft phonon frequencies, and dipole formation. It is found that dipoles formed below the symmetry-lowering phase transition temperature, and they provide the energy gain that drives the phase transition. The calculations and descriptions of CaMnO3 are contained in Chap. I through Chap. III. Chap. II is from a previous paper (Y. R. Chen and P. B. Allen, Phys. Rev. B, 64 064401, 2001) that discusses the formation of polarons in CaMnO3. Chap. III is from another paper (Y. R. Chen, V. Perebeinos, and P. B. Allen, Phys. Rev. B, 65 205207, 2002) which contains discussions for both CaMnO3 and LaMnO3. The part for LaMn3 is included here for completeness. Chap. IV through Chap. VI are related to LDA and the alpha-AlF 3 problem. Chap. V uses the draft of a previous paper of alpha-AlF 3 (Y. R. Chen, V. Perebeinos, and P. B. Allen, Cond-mat/0302272, 2003).