Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Physics

Non-Fermi Liquid Transport And "Universal" Ratios In Quantum Griffiths Phases, David Nozadze, Thomas Vojta Sep 2012

Non-Fermi Liquid Transport And "Universal" Ratios In Quantum Griffiths Phases, David Nozadze, Thomas Vojta

Physics Faculty Research & Creative Works

We use the semi-classical Boltzmann equation to investigate transport properties such as electrical resistivity, thermal resistivity, thermopower, and the Peltier coefficient of disordered metals close to an antiferromagnetic quantum phase transition. In the quantum Griffiths phase, the electrons are scattered by spin-fluctuations in the rare regions. This leads to singular temperature dependencies not just at the quantum critical point, but in the entire Griffiths phase. We show that the resulting non-universal power-laws in transport properties are controlled by the same Griffiths exponent λ which governs the thermodynamics. λ takes the value zero at the quantum critical point and increases throughout …


Transcendental Thermodynamics, Richard E. Morel, George Fleck Jun 2012

Transcendental Thermodynamics, Richard E. Morel, George Fleck

Kahn Institute Projects

Thermodynamics is often viewed as a narrow, introspective discipline, trapped by its origins in the 18th and 19th centuries. By dramatic contrast, we show that the Fourth Law of Thermodynamics provides explanations and interpretations of all natural events, extending across artificial boundaries of tradition- al academic disciplines. The Fourth Law of Thermodynamics states that far-from-equilibrium systems increase entropy at the maximum rate available to them. This broadly inclusive paradigm applies to systems from molecules, to organisms, to the biosphere. The Fourth Law is the Law of Evolution. All systems that communicate with their environment exhibit self-organization and self-optimization, enabling the …


Exact Results In Model Statistical Systems, Peter H. Kleban May 2012

Exact Results In Model Statistical Systems, Peter H. Kleban

University of Maine Office of Research Administration: Grant Reports

Intellectual merit: This project focuses on continued research on the exact study of the statistical mechanics of model systems. The research concentrates on two areas:

1) critical percolation in two dimensions, an important and very extensively studied model system, to which we are bringing new and unexpected approaches, and

2) the thermodynamics of the Farey fraction spin chain, a set of one dimensional models with interesting phase transition behavior and connections to multifractals, and dynamical systems.

This project aims at new results and insights in both these areas. Research on the Farey models illuminates an interesting borderline case in the …


Numerical Study Of The Thermodynamics Of Clinoatacamite, Ehsan Khatami, Joel Helton, Marcos Rigol Feb 2012

Numerical Study Of The Thermodynamics Of Clinoatacamite, Ehsan Khatami, Joel Helton, Marcos Rigol

Faculty Publications

We study the thermodynamic properties of the clinoatacamite compound, Cu2(OH)3Cl, by considering several approximate models. They include the Heisenberg model on (i) the uniform pyrochlore lattice, (ii) a very anisotropic pyrochlore lattice, and (iii) a kagome lattice weakly coupled to spins that sit on a triangular lattice. We utilize the exact diagonalization of small clusters with periodic boundary conditions and implement a numerical linked-cluster expansion approach for quantum lattice models with reduced symmetries, which allows us to solve model (iii) in the thermodynamic limit. We find a very good agreement between the experimental uniform susceptibility and the numerical results for …


Thermodynamics Of Liquid Alkali Metals Using Pseudopotential Perturbation Scheme, Jagendra Kamalsinh Baria, Ashvinkumar Ramaniklal Jani Jan 2012

Thermodynamics Of Liquid Alkali Metals Using Pseudopotential Perturbation Scheme, Jagendra Kamalsinh Baria, Ashvinkumar Ramaniklal Jani

Turkish Journal of Physics

Recently proposed model potential of Baria and Jani is used with the exchange and correlation effect of Sarkar et al. to calculate internal energy (Enthalpy), Entropy and Helmholtz free energy of liquid Na, K, Rb and Cs at various temperatures with the variational approach. The parameter of the potential is determined with the standard zero pressure condition. The structure factor derived by Percus-Yevick solution for hard sphere fluids which is characterized by hard sphere diameter \sigma is used. A good agreement between theoretical investigations and experimental findings has confirmed the ability of the model potential to the liquid alkali metals.


Computational Study Of The Hydration Of Sulfuric Acid Dimers: Implications For Acid Dissociation And Aerosol Formation, Berhane Temelso, Thuong Ngoc Phan, George C. Shields Jan 2012

Computational Study Of The Hydration Of Sulfuric Acid Dimers: Implications For Acid Dissociation And Aerosol Formation, Berhane Temelso, Thuong Ngoc Phan, George C. Shields

Faculty Journal Articles

We have investigated the thermodynamics of sulfuric acid dimer hydration using ab initio quantum mechanical methods. For (H2SO4)2(H2O)n where n = 0−6, we employed high-level ab initio calculations to locate the most stable minima for each cluster size. The results presented herein yield a detailed understanding of the first deprotonation of sulfuric acid as a function of temperature for a system consisting of two sulfuric acid molecules and up to six waters. At 0 K, a cluster of two sulfuric acid molecules and one water remains undissociated. Addition of a second …