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This dissertation describes mainly researches on the chaotic properties of some classical and quantum mechanical systems. New phenomena like the three-dimensional uniform stochastic web and multiply riddled behavior are presented with numerical results. In the introduction, a short history and basic principles about chaotic dynamical systems are reviewed, which include the concepts of Lyapunov exponents and Poincare sections. In Chapter 2, we first discuss the Hamiltonian system, followed by the perturbation and KAM theory, then introduce Arnold diffusion and the existence of stochastic webs. We close this chapter with a system which can generate a three-dimensional uniform stochastic web. In Chapter 3, the relationship between deterministic chaos and quantum mechanics is studied. A quantum mechanical system called the tetrahedral array of Josephson junctions in which the deterministic chaos can exist is presented. At the end, we generalize such systems to any dimension and expect that chaos should survive in a higher dimensional case. In Chapter 4, in addition to the introduction of the riddled behavior, three examples in which multiply riddled behavior can occur are given and illustrated by graphs. The generalization of these systems is also made and we still expect that multiply riddled behavior will exist in these generalized systems containing more degrees of freedom.

"Quantum information" refers to the information-theoretic properties of quantum systems. There is still a general prejudice among physicists against the idea that these systems express information due to the nonlocal behavior of entangled quantum systems. The present paper calculates the information content of simple two-state entangled systems (anti-aligned spin-1/2 electron-positron pair, anti-polarized spin-1 photon pair). This calculation involves a modified application of the entropy formalism of quantum statistical mechanics. In addition, the classical and quantum analogues of mutual information are calculated for the entangled particles and experimental devices used to measure them. It is shown that the amount of information expressed by the spin measurement devices depends upon their parameter settings; the spin information of an entangled system prior to measurement is a constant. These results indicate a distinction between information available to a system's sub-components versus that available to measurement devices outside the system. This "inaccessible" information is likely carried by other physical properties of the system.

Single-molecule DNA experiments dealing with statics and dynamics in nanoconfined systems are typically performed via fluorescence microscopy, yielding access to information regarding molecule conformation but no direct information regarding nanoscale forces. In this experiment, two single-molecule manipulation tools were combined, optical trapping and nanoconfinement, to develop a novel assay that can yield information regarding both molecule conformation and forces experienced in confinement. Single 200nm polystyrene beads are trapped inside 340x340nm silica nanochannels with an entropic nano-slit barrier. These beads are then used as "nano-pistons" or "nanodozers," to apply compressive forces to single-molecules confined inside the nanochannels. In particular, a single nanodozer is used to push a DNA molecule against the barrier, enabling measurements of force versus molecule compression. By carefully calibrating the trap via assessing Brownian motion of an oscillating bead confined in a nanochannel, force-compression curves were obtained and were compared to polymer physics models for a cavity confined chain. / Les experiences traitant de la statique et de la dynamique d'une seule molecule d'ADN dans des systemes nanoconfines sont generalement effectuees par microscopie de fluorescence, donnant acces a l'information concernant la conformation moleculaire, mais aucune information directe concernant les forces a l'echelle nanometrique. Dans cette experience, nous combinons deux outils de manipulation d'une seule molecule, le piegeage optique et le nanoconfinement, an de developper un nouveau test pouvant donner des informations a la fois sur la conformation de la molecule et sur les forces subies en confinement. Des billes de polystyrene de 200nm sont piegees a l'interieur de nanocanaux de silice de dimensions 340x340nm avec une barriere entropique a nano-fente. Ces billes sont ensuite utilisees en tant que "nano-pistons" ou "nanodozers" pour appliquer des forces de compression aux molecules individuelles confinees a l'interieur des nanocanaux. En particulier, un nanodozer unique est utilise pour pousser une molecule d'ADN contre la barriere, permettant une mesure de la force en fonction de la compression moleculaire. En prenant soin de calibrer notre trappe l'aide du mouvement Brownien d'une bille oscillant dans un nanocanal, nous obtenons une courbe force-compression que nous comparons a des modeles physiques de polymeres pour une chaine confinee dans une cavite.

The current excitement surrounding string theory prompted us to tackle the problem of black hole radiation. Claims have been made concerning a possible 'stringy mechanism' that would avoid the singularity problem by giving a divergent energy-dissipation rate. As a check on such arguments, the Casimir energy of the string between two infinite parallel mirrors is computed using the closed, oriented bosonic string. Such a calculation is also a prerequisite to the understanding of the more interesting situation of string behaviour in the presence of accelerating boundaries. The formalism used here is the first-quantized Polyakov approach, which most simply translates to an orbifold problem.

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<p>This paper documents the use of four retarding field analyzers (RFAs) to measure electron cloud signals created in Fermilab's Main Injector during 120 GeV operations. The first data set was taken from September 11, 2009 to July 4, 2010. This data set is used to compare two different types of beam pipe that were installed in the accelerator. Two RFAs were installed in a normal steel beam pipe like the rest of the Main Injector while another two were installed in a one meter section of beam pipe that was coated on the inside with titanium nitride (TiN). A second data run started on August 23, 2010 and ended on January 10, 2011 when Main Injector beam intensities were reduced thus eliminating the electron cloud. This second run uses the same RFA setup but the TiN coated beam pipe was replaced by a one meter section coated with amorphous carbon (aC). This section of beam pipe was provided by CERN in an effort to better understand how an aC coating will perform over time in an accelerator. The research consists of three basic parts: (a) continuously monitoring the conditioning of the three different types of beam pipe over both time and absorbed electrons (b) measurement of the characteristics of the surrounding magnetic fields in the Main Injector in order to better relate actual data observed in the Main Injector with that of simulations (c) measurement of the energy spectrum of the electron cloud signals using retarding field analyzers in all three types of beam pipe. </p>

<p> The non-local fish-bone potential simulates the Pauli-exclusion principle for composite particle interactions. This model is used to calculate the phase shifts of the neutron-alpha and proton-alpha systems. We propose a local double Gaussian potential with a new parameterization by fitting to experimental results. These parameters are universal to both nucleon-alpha systems and include all partial waves, which is an improvement over previous work in the field.</p>

<p> We investigated the properties of magnetic hysteresis loops of Iron Phthalocyanine (FePc) thin films using a Vibrating Sample Magnetometer (VSM). The FePc thin films were deposited onto heated silicon substrates. During deposition the FePc molecules self-assemble into small crystallites ranging in size from 30 to 300 nm on average. Due to the planar shape of the molecule, chains of iron atoms are formed. The magnetic interaction within a chain is much stronger than between chains, making these thin films quasi-one-dimensional magnetic systems. The average length of the major axis of the grains increases with the temperature of the substrate (deposition temperature). Essentially the thin films are made up of many randomly oriented iron chains of variable length, which are parallel to the substrate surface. We show that the coercivity of hysteresis loops measured at 2 K increases linearly with the average major axis grain length. From interpolation, the minimum average grain length for hysteresis to occur is 8 nm, and every additional nano-meter in length increases the coercivity by 72 Oe. By measuring hysteresis loops of many thin films of varying thickness we found that the saturation magnetization is 31 emu/cm³. This corresponds to 2.0 &plusmn; 0.6 &micro;_B per iron ion, as compared to 2.22 &micro;_B for iron in a 3D lattice at 0 K. The choice of substrate also affects the hysteresis properties. Samples deposited on silicon substrates that had first been coated in gold with a rms roughness of approximately 1 nm will show much lower coercivity than corresponding silicon substrate samples. The planar gold surface allows for a different growth pattern in which the chains form vertically, perpendicular to the substrate. This lower coercivity suggests that the chains are shorter when vertically oriented.</p>