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Demonstration Of A Neutral Atom Controlled-Not Quantum Gate, L. Isenhower, E. Urban, X. L. Zhang, A. T. Gill, T. Henage, Todd A. Johnson, T. G. Walker, M. Saffman 2010 College of Saint Benedict/Saint John's University

Demonstration Of A Neutral Atom Controlled-Not Quantum Gate, L. Isenhower, E. Urban, X. L. Zhang, A. T. Gill, T. Henage, Todd A. Johnson, T. G. Walker, M. Saffman

Physics Faculty Publications

We present the first demonstration of a CNOT gate between two individually addressed neutral atoms. Our implementation of the CNOT uses Rydberg blockade interactions between neutral atoms held in optical traps separated by >8  μm. Using two different gate protocols we measure CNOT fidelities of F=0.73 and 0.72 based on truth table probabilities. The gate was used to generate Bell states with fidelity F=0.48±0.06. After correcting for atom loss we obtain an a posteriori entanglement fidelity of F=0.58.


Polymer Length Distributions For Catalytic Polymerization Within Mesoporous Materials: Non-Markovian Behavior Associated With Partial Extrusion, Da-Jiang Liu, Hung-Ting Chen, Victor S.-Y. Lin, James W. Evans 2010 Ames Laboratory

Polymer Length Distributions For Catalytic Polymerization Within Mesoporous Materials: Non-Markovian Behavior Associated With Partial Extrusion, Da-Jiang Liu, Hung-Ting Chen, Victor S.-Y. Lin, James W. Evans

Physics and Astronomy Publications

We analyze a model for polymerization at catalytic sites distributed within parallel linear pores of a mesoporous material. Polymerization occurs primarily by reaction of monomers diffusing into the pores with the ends of polymers near the pore openings. Monomers and polymers undergo single-file diffusion within the pores. Model behavior, including the polymer length distribution, is determined by kinetic Monte Carlo simulation of a suitable atomistic-level lattice model. While the polymers remain within the pore, their length distribution during growth can be described qualitatively by a Markovian rate equation treatment. However, once they become partially extruded, the distribution is shown to ...


Unusual Resistance Hysteresis In N-Layer Graphene Field Effect Transistors Fabricated On Ferroelectric Pb(Zr0.2ti0.8)O3, X. Hong, J. Hoffman, A. Posadas, K. Zou, C. H. Ahn, J. Zhu 2010 University of Nebraska–Lincoln

Unusual Resistance Hysteresis In N-Layer Graphene Field Effect Transistors Fabricated On Ferroelectric Pb(Zr0.2ti0.8)O3, X. Hong, J. Hoffman, A. Posadas, K. Zou, C. H. Ahn, J. Zhu

Xia Hong Publications

We have fabricated n-layer graphene field effect transistors on epitaxial ferroelectric Pb(Zr0.2Ti0.8)O3 (PZT) thin films. At low gate voltages, PZT behaves as a high-k dielectric with k up to 100. An unusual resistance hysteresis occurs in gate sweeps at high voltages, with its direction opposite to that expected from the polarization switching of PZT. The relaxation of the metastable state is thermally activated, with an activation barrier of 50–110 meV and a time constant of 6 h at 300 K. We attribute its origin to the slow dissociation/recombination dynamics ...


Liquid Crystals For Functional Nanomaterials: Electroclinic Artificial Muscle Polymers, Nanorods From Achiral Bent-Core Mesogens, And Thiophenic Photovoltaics, Jacqueline Mae Richardson 2010 University of Colorado at Boulder

Liquid Crystals For Functional Nanomaterials: Electroclinic Artificial Muscle Polymers, Nanorods From Achiral Bent-Core Mesogens, And Thiophenic Photovoltaics, Jacqueline Mae Richardson

Chemistry & Biochemistry Graduate Theses & Dissertations (1986-2018)

Three different projects are described, in which target molecules are synthesized based on specific functional goals: electromechanical response, bent-core phase formation, and charge transport behavior. The bulk properties of these materials are then characterized with respect to these goals.

The first project entails the synthesis and characterization of several variations on W317, a calamitic liquid crystal with a strong electroclinic effect. Alpha, omega-diene analogues of this molecule were synthesized and reacted via ADMET into a main-chain polymer, with the goal of creating electromechanical actuators. To improve the bulk strength and macroscopic response of the polymers, attempts were made at cross-linking ...


Piezoelectric Tuning Of Exchange Bias In A Batio3/Co/Coo Heterostructure, Srinivas Polisetty, W. Echtenkamp, Keith Jones, X. He, Sarbeswar Sahoo, Christian Binek 2010 University of Nebraska-Lincoln

Piezoelectric Tuning Of Exchange Bias In A Batio3/Co/Coo Heterostructure, Srinivas Polisetty, W. Echtenkamp, Keith Jones, X. He, Sarbeswar Sahoo, Christian Binek

Christian Binek Publications

Piezoelectrically controlled strain is used for electric tuning of exchange-bias fields. A generic exchange-bias Co/CoO bilayer is deposited on the surface of a ferroelectric and thus piezoelectric BaTiO3 substrate which allows to apply electrically and thermally tunable stress in the adjacent ferromagnetic Co thin film. The stress-induced strain alters foremost the magnetic anisotropy of the Co film and by that the magnetization orientation at the Co/CoO interface modifying the exchange-bias field. This results in a pronounced electrically induced weakening of the exchange bias but also includes the possibility of tuning the exchange-bias field through a subtle sign ...


Periodic And Quasi-Periodic Responses Of The Earth’S Outer Electron Belt To The Solar Wind With Implications To Space Weather Modeling, Manny Richard Presicci 2010 University of Colorado at Boulder

Periodic And Quasi-Periodic Responses Of The Earth’S Outer Electron Belt To The Solar Wind With Implications To Space Weather Modeling, Manny Richard Presicci

Physics Graduate Theses & Dissertations

It has long been noted the distinct periodicities in the electron flux response in the outer belts are associated with solar wind speed periodicities. The well-organized high-speed streams in the solar wind drive the flux, most commonly resulting in 27, 13.5 and 9-day peaks in the periodogram during the declining phase of the solar cycle. The distribution of peak power across L-shells is calculated and a connection is made with the P1 peak in the impulse response function.

Next, the periodogram estimates the power spectrum relating weak, diffuse periodicities in the number of coronal mass ejection occurrences to relativistic ...


J/Psi Production And Suppression In Au+Au Collisions At Sqrt(S_Nn)=200 Gev, Matthew Gerald Wysocki 2010 University of Colorado at Boulder

J/Psi Production And Suppression In Au+Au Collisions At Sqrt(S_Nn)=200 Gev, Matthew Gerald Wysocki

Physics Graduate Theses & Dissertations

In high-energy heavy ion collisions a partonic state of matter known as the quark-gluon plasma is expected to be formed. The suppression of J/psi meson production in high-energy heavy ion collisions is expected to be a strong signature for the formation of the quark-gluon plasma, due to Debye screening of the quark-antiquark potential. To investigate the state of matter produced in Au+Au collisions at sqrt(sNN)=200 GeV at the PHENIX experiment, we have analyzed forward rapidity J/psi [arrow] μ+μ- production and find that J/psi production is significantly suppressed in collisions at small impact ...


Cold Polar Molecules For Novel Collision Experiments At Low Energies, Brian Sawyer 2010 University of Colorado, Boulder

Cold Polar Molecules For Novel Collision Experiments At Low Energies, Brian Sawyer

Physics Graduate Theses & Dissertations

Research in the field of cold polar molecules is progressing rapidly. An array of interesting

topics is being developed including precision measurement and fundamental tests, quantum phase transitions, and ultracold chemistry. In particular, dipolar molecules in well-defined quantum states enable exquisite control of their interactions via applied electric fields. The long-range, anisotropic interaction between dipolar molecules leads to new collision dynamics that could be used for novel collective effects, quantum state engineering, and information processing. The focus of this Thesis is the production of cold samples of neutral OH molecules via Stark deceleration and magnetic trapping for novel collision experiments ...


Control Of Dipolar Collisions In The Quantum Regime, Marcio H.G. Miranda 2010 University of Colorado, Boulder

Control Of Dipolar Collisions In The Quantum Regime, Marcio H.G. Miranda

Physics Graduate Theses & Dissertations

The preparation of ultracold polar molecular gases close to quantum degeneracy opens novel research prospects ranging from dipolar quantum many-body physics to ultracold chemistry. With a near quantum degenerate gas of fermionic 40K87Rb polar molecules, this thesis presents studies on dipolar collision and chemical reaction dynamics, exhibiting long range interactions and spatial anisotropy. With full control over the internal quantum state of the molecules, we show how quantum statistics of the molecule determines the rate of chemical reactivity in the limit of vanishing collisional energy. Manipulating the interaction potential between indistinguishable polar molecules by means of control ...


Electric-Field Affected Low-Energy Collisions Between Co-Trapped Ammonia And Rubidium, Lambert Paul Parazzoli 2010 University of Colorado at Boulder

Electric-Field Affected Low-Energy Collisions Between Co-Trapped Ammonia And Rubidium, Lambert Paul Parazzoli

Physics Graduate Theses & Dissertations

This thesis describes the effect of an electric field on the interaction between rubidium and ammonia at 100 mK. The ability to study low energy interactions between molecules and atoms provides new tools to understand how the processes that govern these interactions work. For example, the use of external electric and magnetic fields provides tools to spatially orient molecules to show how this affects the dynamics of the interaction. The use of electric fields have been proposed to affect dipole-dipole interactions, however we have showed that the space-orienting effect of the field can have a significant effect even in the ...


Probing An Interacting Bose Gas In A Quasi-Two-Dimensional Trap, Shihkuang Tung 2010 University of Colorado, Boulder

Probing An Interacting Bose Gas In A Quasi-Two-Dimensional Trap, Shihkuang Tung

Physics Graduate Theses & Dissertations

A fluctuating regime associated with the Berenzinskii-Kosterlitz-Thouless (BKT) transition is studied in a two-dimensional system of near-degenerate bosons (87Rb atoms). Two imaging procedures, the in-situ imaging method and the focusing-imaging method, are implemented to image the coordinate-space and momentum-space density distributions. The scaled compressibility is extracted from the coordinate-space density distributions obtained from in-situ images. Comparing the measured compressibility to the prediction from our semiclassical mean-field model, an onset of a regime which is beyond the mean-field prediction is identified and first resolved at phase-space density 2 ≥ 3. Information about the coherence of the system is extracted from ...


Towards Measuring The Electron Electric Dipole Moment Using Trapped Molecular Ions, Russell Stutz 2010 University of Colorado, Boulder

Towards Measuring The Electron Electric Dipole Moment Using Trapped Molecular Ions, Russell Stutz

Physics Graduate Theses & Dissertations

Permanent electric dipole moments have been the subject of experimental investigation for the past sixty years, as they entail the breaking of fundamental symmetries and provide a sensitive probe for physics beyond the Standard Model. This thesis describes an experiment aimed at measuring the electron electric dipole moment (eEDM) using trapped molecular ions. The 3Δ1 level of certain diatomic ions are desirable in eEDM searches due to their high polarizability, large eEDM enhancement factor, and relative insensitivity to magnetic fields. Ions allow for simple trapping and long interrogation times, but require a time-varying electric bias field in order ...


Two-Species Ion Arrays For Quantum Logic Spectroscopy And Entanglement Generation, David Brian Hume 2010 University of Colorado, Boulder

Two-Species Ion Arrays For Quantum Logic Spectroscopy And Entanglement Generation, David Brian Hume

Physics Graduate Theses & Dissertations

The quantum states of trapped atomic ions can be highly isolated from external perturbation, and precisely manipulated with applied laser fields. This makes them an excellent medium for quantum-limited experiments such as quantum information processing and precision spectroscopy. A relatively small number of ion species have been used for these types of experiments because most species are difficult to laser cool and detect directly. This thesis demonstrates a way to overcome this limitation by use of sympathetic cooling and state detection based on quantum logic. We apply these techniques to mixed-species arrays of Al+ and Be+ ions. A mathematical model ...


Aging To Equilibrium Dynamics Of Sio2, Katharina Vollmayr-Lee, J. A. Roman, J. Horbach 2010 Bucknell University

Aging To Equilibrium Dynamics Of Sio2, Katharina Vollmayr-Lee, J. A. Roman, J. Horbach

Faculty Journal Articles

No abstract provided.


Probing Equilibrium By Nonequilibrium Dynamics: Aging In Co/Cr Superlattices, Tathagata Mukherjee, M. Pleimling, Christian Binek 2010 University of Nebraska–Lincoln

Probing Equilibrium By Nonequilibrium Dynamics: Aging In Co/Cr Superlattices, Tathagata Mukherjee, M. Pleimling, Christian Binek

Christian Binek Publications

Magnetization relaxation is investigated in a structurally ordered magnetic Co/Cr superlattice. Tailored nanoscale periodicity creates mesoscopic spatial magnetic correlations with slow relaxation dynamics when quenching the system into a nonequilibrium state. Magnetization transients are measured after exposing the heterostructure to a magnetic set field for various waiting times. Scaling analysis reveals an asymptotic powerlaw behavior in accordance with a full aging scenario. The temperature dependence of the relaxation exponent shows pronounced anomalies at the equilibrium phase transitions of the antiferromagnetic superstructure and the ferromagnetic to paramagnetic transition of the Co layers. The latter leaves only weak fingerprints in the ...


Near-Field Radiative Transfer: Thermal Radiation, Thermophotovoltaic Power Generation And Optical Characterization, Mathieu Francoeur 2010 University of Kentucky

Near-Field Radiative Transfer: Thermal Radiation, Thermophotovoltaic Power Generation And Optical Characterization, Mathieu Francoeur

University of Kentucky Doctoral Dissertations

This dissertation focuses on near-field radiative transfer, which can be defined as the discipline concerned with energy transfer via electromagnetic waves at sub-wavelength distances. Three specific subjects related to this discipline are investigated, namely nearfield thermal radiation, nanoscale-gap thermophotovoltaic (nano-TPV) power generation and optical characterization. An algorithm for the solution of near-field thermal radiation problems in one-dimensional layered media is developed, and several tests are performed showing the accuracy, consistency and versatility of the procedure. The possibility of tuning near-field radiative heat transfer via thin films supporting surface phononpolaritons (SPhPs) in the infrared is afterwards investigated via the computation of ...


Measurement Of Single-Target Spin Asymmetries In The Electroproduction Of Negative Pions In The Semi-Inclusive Deep Inelastic Reaction N↑(E,Éπ¯)X On A Transversely Polarized 3he Target, Chiranjib Dutta 2010 University of Kentucky

Measurement Of Single-Target Spin Asymmetries In The Electroproduction Of Negative Pions In The Semi-Inclusive Deep Inelastic Reaction N↑(E,Éπ¯)X On A Transversely Polarized 3he Target, Chiranjib Dutta

University of Kentucky Doctoral Dissertations

The experiment E06010 measured the target single spin asymmetry (SSA) in the semiinclusive deep inelastic (SIDIS) n↑(e,éπ¯)X reaction with a transversely polarized 3He target as an effective neutron target. This is the very first independent measurement of the neutron SSA, following the measurements at HERMES and COMPASS on the proton and the deuteron. The experiment acquired data in Hall A at Jefferson Laboratory with a continuous electron beam of energy 5.9 GeV, probing the valence quark region, with x = 0.13→0.41, at Q2 = 1.31→3.1 GeV2. The two contributing ...


Tunneling Spectroscopy Study Of Calcium Ruthenate, Anthony Bautista 2010 University of Kentucky

Tunneling Spectroscopy Study Of Calcium Ruthenate, Anthony Bautista

University of Kentucky Doctoral Dissertations

The ruthenates are perhaps one of the most diverse group of materials known up to date. These compounds exhibit a wide array of behaviors ranging from the exotic pwave superconductivity in Sr2RuO4, to the itinerant ferromagnetism in SrRuO3, and the Mott-insulating behavior in Ca2RuO4. One of the most intriguing compounds belonging to this group is Ca3Ru2O7 which is known to undergo an antiferromagnetic ordering at 56K and an insulating transition at 48K. Most intriguing, however, is the behavior displayed by this compound in the presence of an external ...


Type-1.5 Superconducting State From An Intrinsic Proximity Effect In Two-Band Superconductors, Egor Babaev, Johan Carlstrom, Martin Speight 2010 University of Massachusetts - Amherst

Type-1.5 Superconducting State From An Intrinsic Proximity Effect In Two-Band Superconductors, Egor Babaev, Johan Carlstrom, Martin Speight

Physics Department Faculty Publication Series

We show that in multiband superconductors, even an extremely small interband proximity effect can lead to a qualitative change in the interaction potential between superconducting vortices by producing long-range intervortex attraction. This type of vortex interaction results in an unusual response to low magnetic fields leading to phase separation into domains of two-component Meissner states and vortex droplets.


Regge Kinematics In Soft Collinear Effective Theory, JF Donoghue, D Wyler 2010 University of Massachusetts Amherst

Regge Kinematics In Soft Collinear Effective Theory, Jf Donoghue, D Wyler

Physics Department Faculty Publication Series

We discuss the kinematics of the particles that make up a Reggeon in field theory, using the terminology of the soft collinear effective theory (SCET). Reggeization sums a series of strongly ordered collinear emissions resulting in an overall Reggeon exchange that falls in the Glauber or Coulomb kinematic region. This is an extremely multiscale problem and appears to fall outside of the usual organizing scheme of SCET.


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