Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 24 for “"finite-size scaling"”.
-
Correlation Lengths and Times in Copper Manganese Spin Glasses From Simulation and Experiment
… field-dependent aging and measurements of finite-size effects are used to study correlation lengths and times of Cu1-xMn x spin glasses. Several results are found: a single model inspired by the Parisi solution explains both the experimentally observed aging and equilibrium fluctuation …
-
Correlation lengths and times in CuMn spin glasses from simulation and experiment
… field-dependent aging and measurements of finite-size effects are used to study correlation lengths and times of Cul-xMnx spin glasses. Several results are found: a single model inspired by the Parisi solution explains both the experimentally observed aging and equilibrium fluctuation …
-
Monte Carlo analysis of non-equilibrium steady states and relaxation kinetics in driven lattice gases
… precise Monte Carlo simulations of larger system sizes than previous studies. In the one-dimensional asymmetric exclusion process on a ring with half the lattice sites occupied, we find that correlations induce extremely slow relaxation to the asymptotic power law decay We compare the crossover …
-
Examining the Dynamics of Biologically Inspired Systems Far From Equilibrium
… the depth and location of this minimum to obey finite-size scaling laws that suggest the system is undergoing a second-order phase transition. We can use these finite-size scaling relations to further optimize this system by tuning it to the critical point for any given system size.
-
The one-dimensional spin-1/2 ANNNI model in non-commuting magnetic fields
… heats were calculated. By application of the finite-size scaling technique it was possible to obtain the phase boundaries of the model numerically. For certain limits of the full Hamiltonian we compared the obtained results with the existing literature and we got good agreement.
-
Wärmeleitfähigkeit von 4 He in der Nähe des superfluiden Phasenübergangs in begrenzter Geometrie
… a 2nd order phase transition. For the infinite system very precise calculations based on renormalization group theory have been published. In most cases there is good agreement of the theoretical predictions with both experiment and computer simulation. This comparison confirms the main …
-
The doping and magnetic field dependence of the heat capacity of yttrium barium copper oxide superconductors
… into account the effects of fluctuations and finite-size scaling. The method of fitting was motivated by measurements of the field dependence of the heat capacity upon the removal of oxygen, which indicate that the fluctuations are best approximated as being in the critical regime for all …
-
Strongly coupled systems : from quantum antiferromagnets to unified models for superconductors
… in various spin representations S. Using a finite-size-scaling technique, we explored correlation lengths of up to 105 lattice spacings for spins S=1 and 5/2. We show how the recent prediction of cutoff effects by P. Hasenfratz is approached for moderate correlation lengths, and smoothly …
-
Superconductor-insulator transition induced by electrostatic charging in high temperature superconductors.
… an ionic liquid as the dielectric. Employing a finite size scaling analysis, curves of resistance versus temperature, R(T), over the temperature range from 6 K to 22 K were found to collapse onto a single function, which suggests the presence of a quantum critical point. However the scaling …
-
An Exploration of Quantum Critical Phenomena in One-Dimensional Lattice Systems: Geometric Frustration & Quantum Fluctuations
… main focus will be on the use of entanglement scaling as an indicator of when a phase transition has occurred, more specifically for first-order quantum phase transitions in the vicinity of second-order quantum phase transitions. In this context, we show the dramatic importance of finite-size …
-
Disorder at first-order classical and quantum phase transitions
… covers the basic concepts of phase transitions, finite-size scaling and random disorder, the dissertation focuses on four separate but related projects. First, we investigate the influence of quenched disorder with long-range spatial correlations on the nonequilibrium phase transitions in the …
-
Numerical studies of the critical behaviour of non-commutative field theories
… point for a system constructed of matrices of size N = 7. Our numerical results also suggest the existence of stripe phases- phases in which modes with higher momentum l have non-negligible contribution. The second system under study is a matrix model realized via competing Yang-Mills and Myers …
-
Approach to equilibrium in systems with continuous symmetries
… is observed at early times in two dimensions. Finite-size scaling of the scattering function is demonstrated and it is shown that dynamical scaling is satisfied not only by the correlation functions of the order parameter but also by the correlation functions of the defects (point-vortices in …
-
Spin Systems far from Equilibrium: Aging and Dynamic Phase Transition
… length L(t) is determined numerically and the scaling behavior of various two-time quantities as a function of L(t)/L(s) is discussed where t and s are two different times. For disordered Ising models deviations of L(t) from algebraic growth law show up. The generalized scaling forms as a …
-
Steady State Properties of Some Driven Diffusive Systems
… find the phase diagram of the system, perform a finite-size scaling study in order to determine the universality class of the model and compare our simulation results with the phase diagram obtained using the high temperature expansion. We conclude that the bias in the jump rates does not affect …
-
Feedback Control Theory in Stochastic Dynamical Systems
… For classical model, I perform a study on finite-size effects at the phase transition in the Nagel-Schreckenberg traffic model as an example of non-equilibrium many body stochastic dynamical system. For quantum mechanical model, I introduce an optimal measurement-based feedback control …
-
Computational Study of Colloids in Suspension: Effective Interactions and Phase Transitions
… study of effective interactions between micron-sized silica spheres, induced by highly charged zirconia nanoparticles. Explicit modeling of the colloidal particles and nanoparticles demonstrates that the effective interactions induced by nanoparticles are responsible for a colloidal …
-
Dynamic weakening and trained memory in avalanche dynamics from high-entropy alloys to neurons and spin systems
… share universal features such as broad event-size distributions and scale-invariant critical phenomena. A simple depinning theory provides a unifying framework for these behaviors, yet many systems deviate from pure criticality, exhibiting system-spanning runaways, characteristic length …
-
Approach to equilibrium in systems with continuous symmetries
… the initial ordering process in the system. Finite-size scaling of the scattering function is demonstrated and it is shown that dynamical scaling is satisfied not only by the correlation functions of the order parameter but also by the correlation functions of the defects (point-vortices in …
-
Non-Equilibrium Pattern Formation in Multi-Species Interacting Particle Systems
… macroscopic demixing perpendicular to the drive. Finite-size scaling analysis indicates that there is no critical driving force associated with demixing, which appears as a crossover in finite systems. We attribute this effect to the disruption of long-ranged order by the transient jammed …
Page 1 of 2