Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
Constructing Explicit Magnetic Analogies For The Dynamics Of Glass Forming Liquids, Jacob D. Stevenson, Aleksandra M. Walczak, Randall W. Hall, Peter G. Wolynes
Constructing Explicit Magnetic Analogies For The Dynamics Of Glass Forming Liquids, Jacob D. Stevenson, Aleksandra M. Walczak, Randall W. Hall, Peter G. Wolynes
Randall W. Hall
By defining a spatially varying replica overlap parameter for a supercooled liquid referenced to an ensemble of fiducial liquid state configurations, we explicitly construct a constrained replica free energy functional that maps directly onto an Ising Hamiltonian with both random fields and random interactions whose statistics depend on the liquid structure. Renormalization group results for random magnets when combined with these statistics for the Lennard-Jones glass suggest that discontinuous replica symmetry breaking would occur if a liquid with short range interactions could be equilibrated at a sufficiently low temperature where its mean field configurational entropy would vanish, even though the …
An Order Model For Infinite Classical States, Joe Mashburn
An Order Model For Infinite Classical States, Joe Mashburn
Joe D. Mashburn
In 2002 Coecke and Martin (Research Report PRG-RR-02-07, Oxford University Computing Laboratory,2002) created a model for the finite classical and quantum states in physics. This model is based on a type of ordered set which is standard in the study of information systems. It allows the information content of its elements to be compared and measured. Their work is extended to a model for the infinite classical states. These are the states which result when an observable is applied to a quantum system. When this extended order is restricted to a finite number of coordinates, the model of Coecke and …
Constructing Explicit Magnetic Analogies For The Dynamics Of Glass Forming Liquids, Jacob D. Stevenson, Aleksandra M. Walczak, Randall W. Hall, Peter G. Wolynes
Constructing Explicit Magnetic Analogies For The Dynamics Of Glass Forming Liquids, Jacob D. Stevenson, Aleksandra M. Walczak, Randall W. Hall, Peter G. Wolynes
Randall W. Hall
By defining a spatially varying replica overlap parameter for a supercooled liquid referenced to an ensemble of fiducial liquid state configurations, we explicitly construct a constrained replica free energy functional that maps directly onto an Ising Hamiltonian with both random fields and random interactions whose statistics depend on the liquid structure. Renormalization group results for random magnets when combined with these statistics for the Lennard-Jones glass suggest that discontinuous replica symmetry breaking would occur if a liquid with short range interactions could be equilibrated at a sufficiently low temperature where its mean field configurational entropy would vanish, even though the …
Constructing Explicit Magnetic Analogies For The Dynamics Of Glass Forming Liquids, Jacob D. Stevenson, Aleksandra M. Walczak, Randall W. Hall, Peter G. Wolynes
Constructing Explicit Magnetic Analogies For The Dynamics Of Glass Forming Liquids, Jacob D. Stevenson, Aleksandra M. Walczak, Randall W. Hall, Peter G. Wolynes
Randall W. Hall
By defining a spatially varying replica overlap parameter for a supercooled liquid referenced to an ensemble of fiducial liquid state configurations, we explicitly construct a constrained replica free energy functional that maps directly onto an Ising Hamiltonian with both random fields and random interactions whose statistics depend on the liquid structure. Renormalization group results for random magnets when combined with these statistics for the Lennard-Jones glass suggest that discontinuous replica symmetry breaking would occur if a liquid with short range interactions could be equilibrated at a sufficiently low temperature where its mean field configurational entropy would vanish, even though the …
Benchmark Structures And Binding Energies Of Small Water Clusters With Anharmonicity Corrections, Berhane Temelso, Kaye A. Archer, George C. Shields
Benchmark Structures And Binding Energies Of Small Water Clusters With Anharmonicity Corrections, Berhane Temelso, Kaye A. Archer, George C. Shields
Berhane Temelso
For (H2O)n where n = 1–10, we used a scheme combining molecular dynamics sampling with high level ab initio calculations to locate the global and many low lying local minima for each cluster. For each isomer, we extrapolated the RI-MP2 energies to their complete basis set limit, included a CCSD(T) correction using a smaller basis set and added finite temperature corrections within the rigid-rotor-harmonic-oscillator (RRHO) model using scaled and unscaled harmonic vibrational frequencies. The vibrational scaling factors were determined specifically for water clusters by comparing harmonic frequencies with VPT2 fundamental frequencies. We find the CCSD(T) correction to the RI-MP2 binding …
Critical Phenomena And Estimation Of The Spontaneous Magnetization By A Magnetic Entropy Analysis In Mn0.96nb0.04coge Alloy, Jyotish C. Debnath, A M. Strydom, P Shamba, Jianli Wang, S X. Dou
Critical Phenomena And Estimation Of The Spontaneous Magnetization By A Magnetic Entropy Analysis In Mn0.96nb0.04coge Alloy, Jyotish C. Debnath, A M. Strydom, P Shamba, Jianli Wang, S X. Dou
Shi Xue Dou
Magnetic and magnetocaloric properties of the alloy Mn0.96Nb0.04CoGe have been investigated.
Magnetic Phase Transitions And Entropy Change In Layered Ndmn1.7cr0.3si2, M F. Md Din, Jianli Wang, S J. Campbell, A J. Studer, M Avdeev, S J. Kennedy, Q F. Gu, R Zeng, S X. Dou
Magnetic Phase Transitions And Entropy Change In Layered Ndmn1.7cr0.3si2, M F. Md Din, Jianli Wang, S J. Campbell, A J. Studer, M Avdeev, S J. Kennedy, Q F. Gu, R Zeng, S X. Dou
Shi Xue Dou
A giant magnetocaloric effect has been observed around the Curie temperature, TC ∼ 42 K, in NdMn1.7Cr0.3Si2 with no discernible thermal and magnetic hysteresis losses. Below 400 K, three magnetic phase transitions take place around 380 K, 320 K and 42 K. Detailed high resolution synchrotron and neutron powder diffraction (10-400 K) confirmed the magnetic transitions and phases as follows: TN intra ∼ 380 K denotes the transition from paramagnetism to intralayer antiferromagnetism (AFl), TN inter ∼ 320 K represents the transition from the AFl structure to the canted antiferromagnetic spin structure (AFmc), while TC ∼ 42 K denotes the …
Investigation Of The Critical Behavior In Mn0.94nb 0.06coge Alloy By Using The Field Dependence Of Magnetic Entropy Change, J C. Debnath, P Shamba, A M. Strydom, Jianli Wang, S X. Dou
Investigation Of The Critical Behavior In Mn0.94nb 0.06coge Alloy By Using The Field Dependence Of Magnetic Entropy Change, J C. Debnath, P Shamba, A M. Strydom, Jianli Wang, S X. Dou
Jianli Wang
The critical behaviour of Mn0.94Nb0.06CoGe alloy around the paramagnetic-ferromagnetic phase transition was studied based on the field dependence on magnetic entropy change. By using the obtained exponents, the modified Arrott plot is consistent with that by using conventional method. These critical exponents are confirmed by the Widom scaling relation. Based on these critical exponents, the magnetization, field and temperature data around Tc collapse into two curves obeying the single scaling equation MðH; e)¼ebf6(H/ebþc). The calculated critical exponents not only obey the scaling theory but also anastomose the deduced results from the Kouvel-Fisher method [J. S. Kouvel and M. E. Fisher, …
Investigation Of The Critical Behavior In Mn0.94nb 0.06coge Alloy By Using The Field Dependence Of Magnetic Entropy Change, J C. Debnath, P Shamba, A M. Strydom, Jianli Wang, S X. Dou
Investigation Of The Critical Behavior In Mn0.94nb 0.06coge Alloy By Using The Field Dependence Of Magnetic Entropy Change, J C. Debnath, P Shamba, A M. Strydom, Jianli Wang, S X. Dou
Shi Xue Dou
The critical behaviour of Mn0.94Nb0.06CoGe alloy around the paramagnetic-ferromagnetic phase transition was studied based on the field dependence on magnetic entropy change. By using the obtained exponents, the modified Arrott plot is consistent with that by using conventional method. These critical exponents are confirmed by the Widom scaling relation. Based on these critical exponents, the magnetization, field and temperature data around Tc collapse into two curves obeying the single scaling equation MðH; e)¼ebf6(H/ebþc). The calculated critical exponents not only obey the scaling theory but also anastomose the deduced results from the Kouvel-Fisher method [J. S. Kouvel and M. E. Fisher, …
Giant Magnetic Entropy Change In Colossal Magnetoresistance In La0.7ca0.3mno3 Material In Low Field, Jyotish Debnath, Rong Zeng, Jung Ho Kim, S X. Dou
Giant Magnetic Entropy Change In Colossal Magnetoresistance In La0.7ca0.3mno3 Material In Low Field, Jyotish Debnath, Rong Zeng, Jung Ho Kim, S X. Dou
Shi Xue Dou
The structural, magnetic, and magnetocaloric properties of the manganite La0.7Ca0.3MnO3 have been studied. Change in the giant magnetic entropy was observed without any noticeable magnetic hysteresis but with small thermal hysteresis losses. We observed a first order magnetic phase transition around 251 K. The magnetic entropy change observed in this work is estimated to be 5.27 J/kg K for field changes from 0 to 1.5 T based on magnetization measurements. This value is about twice as large as those for other perovskite manganites and is even larger than for Gd-based magnetic materials at low fields. In addition, the entropy change …
A New Class Of Entropy Estimators For Multi-Dimensional Densities, Erik G. Learned-Miller
A New Class Of Entropy Estimators For Multi-Dimensional Densities, Erik G. Learned-Miller
Erik G Learned-Miller
We present a new class of estimators for approximating the entropy of multi-dimensional probability densities based on a sample of the density. These estimators extend the classic "m-spacing" estimators of Vasicek (1976) and others for estimating entropies of one-dimensional probability densities. Unlike plug-in estimators of entropy, which first estimate a probability density and then compute its entropy. our estimators avoid the difficult intermediate step of density estimation. For fixed dimension. the estimators an polynomial in the sample size. Similarities to consistent and asymptotically efficient one-dimensional estimators of entropy suggest that our estimators may sham these properties.