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111Th Statistical Mechanics Conference Short Talk Schedule Session A 111th Statistical Mechanics Conference Short Talk Schedule Session A A01 : Ge Zhang, Princeton University Coauthor(s): Ge Zhang*, Frank H. Stillinger, and Salvatore Torquato Disordered classical ground states of collective coordinate potentials We use a collective-coordinates approach to study disordered classical ground states of particles interacting with certain pair potentials across the first three Euclidean space dimensions. In particular, we characterize their pair statistics in both direct and Fourier spaces as a function of a control parameter that varies the degree of disorder. A02 : Michael A. Klatt, Department of Chemistry and Department of Physics, Princeton University Coauthor(s): Salvatore Torquato Characterizing Maximally Random Jammed Sphere Packings using Minkowski Functionals and Tensors Department of Chemistry and Department of Physics, Princeton UniversityWe characterize the structure of maximally random jammed (MRJ) sphere packings using Minkowski functionals and tensors. The MRJ state is roughly speaking the most disordered sphere packing that is simultaneously jammed (mechanically stable). We construct the Voronoi diagram and characterize the shape of the Voronoi cells using scalar Minkowski functionals, i.e., volume, surface area, and integrated mean curvature, and also their tensorial extensions, e.g., the moment tensor of the normal distribution. A03 : Steven Atkinson, Department of Mechanical and Aerospace Engineering, Princeton University Coauthor(s): S. Atkinson, F. H. Stillinger, and S. Torquato Rattlers in Maximally Random Jammed Packings of Hard-Spheres We use the Torquato-Jiao Sequential Linear Programming algorithm [S. Torquato and Y. Jiao, Phys. Rev. E. 82, 061302 (2010)] to generate exactly isostatic, strictly jammed packings of monodisperse hard-spheres of exquisite numerical fidelity that come closer to the true MRJ state than ever before. The average rattler fraction of these packings is markedly lower than previous estimates, prompting us to perform a detailed characterization of the rattler population. We find strikingly correlated spatial behavior, contrary to the conventional understanding that they be randomly distributed. In particular, we observe dynamically-interacting "polyrattlers" with cluster sizes of up to five rattlers in system sizes up to 2000 spheres, showing that MRJ packings of monodisperse spheres can contain large rattler cages while still obeying the strict jamming criterion. A04 : Duyu Chen, Department of Chemistry, Princeton University Coauthor(s): Yang Jiao, Salvatore Torquato Equilibrium Phase Behavior and Maximally Random Jammed State of Truncated Tetrahedra Systems of hard nonspherical particles exhibit a variety of stable phases with different degrees of translational and orientational order, including isotropic liquid, solid crystal, rotator and a variety of liquid crystal phases. In this work, we employ a Monte Carlo implementation of the adaptive-shrinking-cell (ASC) numerical scheme and free-energy calculations to ascertain with high precision the equilibrium phase behavior of systems of congruent Archimedean truncated tetrahedra over the entire density range. In particular, we find that the system undergoes two first-order phase transitions as the density increases: first a liquid-solid transition and then a solid- solid transition. The isotropic liquid phase coexists with the Conway-Torquato (CT) crystal phase at intermediate densities. At higher densities, we find that the CT phase undergoes another first-order phase transition to one associated with the densest-known crystal. We find no evidence for stable rotator (or plastic) or nematic phases. We also generate the maximally random jammed (MRJ) packings of truncated tetrahedra, which may be regarded to be the glassy end state of a rapid compression of the liquid. We find that such MRJ packings are hyperuniform with an average packing fraction of 0.765, which is considerably larger than the corresponding value for identical spheres (around 0.64). We conclude with some simple observations concerning what types of phase transitions might be expected in hard-particle systems based on the particle shape. A05 : Dima Bolmatov, Baker Lab, Cornell University The Phonon Theory of Liquid Thermodynamics and New Understanding of Supercritical State Heat capacity of matter is considered to be its most important property because it holds information about system's degrees of freedom. Heat capacity is well understood in gases and solids but not in the third main state of matter, liquids, and is not discussed in physics textbooks as a result. The perceived difficulty is that interactions in a liquid are both strong and system-specific, implying that the energy strongly depends on the liquid type and that, therefore, liquid energy cannot be calculated in general form. Here, I formulate the problem in the language of phonons, and calculate liquid energy and heat capacity for both classical and quantum regimes. The resulting equation relates liquid heat capacity to its relaxation time with no fitting parameters. I subsequently discuss how thermodynamic properties of the liquid evolve above the critical point using the recent idea that the mean-free path defines the minimal wavelength of longitudinal phonons in the system and our recent finding of the crossover of liquid specific heat in the supercritical state. I finally discuss the new Frenkel line recently proposed to exist in the supercritical state. Contrary to the existing view, we have shown that the supercritical state is not physically uniform in terms of physical properties, but exists in two distinct states: "rigid" liquids and "non-rigid" gas-like fluids separated by a smooth transition across the Frenkel line on the phase diagram. All major properties of the system, including diffusion, viscosity, thermal conductivity, speed of sound and heat capacity as well as structure all undergo qualitative changes at the Frenkel line, from the liquid-like to gas-like A06 : Vasily Geyko, Princeton University Coauthor(s): N.J. Fisch Modified Engine Cycle with Spinning Gas A gas spinning at sonic velocities has an effectively higher heat capacity, which can be used to modify engine fuel cycles. A remarkable gain in fuel efficiency is shown to be theoretically possible for the Otto and Diesel cycles. Neglecting inefficiencies in producing the spinning, the theoretical maximum fuel efficiencies of Otto cycle engines might be increased by as much as 10%-40%. Low-temperature, clean-burning engine cycles might, in principle, benefit even more from a spinning working gas. A07 : Eugene Kolomeisky, University of Virginia Coauthor(s): Joseph P. Straley and Hussain Zaidi Fermion space charge in narrow-band gap semiconductors, Weyl semimetals and around highly charged nuclei} The field of charged impurities in narrow-band gap semiconductors and Weyl semimetals can create electron-hole pairs when the total charge $Ze$ of the impurity exceeds a value $Z_{c}e.$ The particles of one charge escape to infinity, leaving a screening space charge. The result is that the observable dimensionless impurity charge $Q_{\infty}$ is less than $Z$ but greater than $Z_{c}$. There is a corresponding effect for nuclei with $Z >Z_{c} \approx 170$, however in the condensed matter setting we find $Z_{c} \simeq 10$. Thomas-Fermi theory indicates that $Q_{\infty} = 0$ for the Weyl semimetal, but we argue that this is a defect of the theory. For the case of a highly-charged recombination center in a narrow band-gap semiconductor (or of a supercharged nucleus), the observable charge takes on a nearly universal value. In Weyl semimetals the observable charge takes on the universal value $Q_{\infty} = Z_{c}$ set by the reciprocal of material's fine structure constant. A08 : Klaus Mecke, University of Erlangen-Nuremberg Topology of confinement is visible in thermodynamics Fluctuation phenomena in small-scale systems depend on the shape of the system, in particular on the topology of the confining wall. If motion invariance, continuity, and additivity of the free nergy are satisfied, only four morphometric measures are needed to describe fully the influence of an arbitrarily shaped container on the fluid. These three constraints can be understood as a more precise definition for the conventional term 'extensivity' and have as a consequence that the surface tension and other thermodynamic quantities contain, aside from a constant term, only contributions linear in the mean and Gaussian curvature of the container and not an infinite number of curvatures as generally assumed before. We verify this numerically in the entropic system of hard spheres bounded by a curved wall, and show deviations for lattice systems such as the spherical model and the Ising model. A09 : Mohammad Fassihi, Amir-Kabir Tehran Application of the Confined Quantum Field Theory in the Statistical Physics. Confined Quantum Field Theory solves some fundamental problems in physics like the conflict between the theory of the relativity and the quantum field theory. Concerning statistical physics is its simple description of superconductivity and super fluidity, which is a transition from disorder to order movement of the conducting electrons. A10 : Leonid Pryadko, UC, Riverside Coauthor(s): Alexey Kovalev (UNL) Spin glass reflection of the decoding transition for quantum error correcting codes We study the decoding transition for quantum error correcting codes with the help of a mapping to random-bond Wegner spin models. Families of quantum
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