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 23 for “"spin models"”.
-
Spectral and dynamical properties of disordered and noisy quantum spin models
… and dynamical characteristics of certain quantum spin systems in the presence of either I) quenched disorder, or II) dynamical noise. In the first part, the quantum random energy model (QREM), a mean-field spin glass model with a many-body localisation transition, is studied. In Chapter 2, we …
-
Realizing quantum spin models with ⁷Li atoms in an optical lattice
Quantum spin Hamiltonians are paradigmatic models, which display different kinds of quantum phase transitions, strongly-correlated and topological ground states, and various regimes of transport. Expanding their significance, many mappings exist between quantum spin models and other systems in …
-
Non-equilibrium dynamics in three-dimensional magnetic spin models and molecular motor-inspired one-dimensional exclusion processes
… of three-dimensional antiferromagnetic lattice spin models with Heisenberg interaction following a critical quench, and a one-dimensional exclusion process inspired by the gear-like motion of molecular motors. In a system of three-dimensional Heisenberg antiferromagnets the non-conserved …
-
Utilizing Hierarchical Clusters in the Design of Effective and Efficient Parallel Simulations of 2-D and 3-D Ising Spin Models
… parallel Monte Carlo algorithms for the Ising spin model on a hierarchical cluster. A hierarchical cluster can be considered as a cluster of homogeneous nodes which are partitioned into multiple supernodes such that communication across homogenous clusters is represented by a supernode …
-
Studies of Topology and Order in Frustrated Spin Systems
… between topology and order in frustrated quantum spin systems. We identify the relevant effects in the study of novel phases of matter, as they emerge in tractable quantum spin models, and we make several original contributions. In this dissertation, (a) we study quantum dimer models with …
-
Quantum Statistical Physics of a Microscopic Glass Model
… and find relations to quantum spherical p-spin models.
-
Exploring spin physics with ultracold atoms
The dynamics of many interacting spins is an active frontier of research; not only can they explain magnetic phenomena, but they also provide paradigmatic models with deep connections to high-T_c superconductivity, optimization problems, neural networks, and more. Experiments with ultracold alkali …
-
Time Reparametrization Symmetry and Spatial-Temporal Fluctuations in Glasses
… to be present in the Edwards-Anderson model of spin glasses and in the mean field equations of p-spin models. We study time reparametrization symmetry in p-spin models of arbitrary interaction range. Starting from the Martin-Siggia-Rose generating functional, we analytically probe the long-time …
-
Quantum Simulation of Spin-1 Physics with Bosons in Optical Lattice
… with Mott insulators is the study of quantum spin models, which are intimately connected to other modern research topics such as the study of quantum phase transitions and quantum thermalization. While quantum spin models are also realized and have traditionally been studied with complex …
-
Application of advanced diagonalization methods to quantum spin systems.
Quantum spin models play an important role in theoretical condensed matter physics and quantum information theory. One numerical technique that is frequently used in studies of quantum spin systems is exact diagonalization. In this approach, numerical methods are used to find the lowest eigenvalues …
-
Thermodynamics of 5-flavor QCD
… using Monte Carlo simulations of improved ϕ⁴ models. We extract parametrizations of the Z(2) and O(2) scaling functions to high precisions by fitting data from simulations of the respective spin models.
-
On the partition function for the three-dimensional Ising model
… to investigate the critical behaviour of lattice spin models such as the three-dimensional Ising model in the thermodynamic limit. The exact partition functions (typically summed over the order of 1075 states) for finite simple cubic Ising lattices are computed using a transfer matrix approach. …
-
Introduction to fast Super-Paramagnetic Clustering
We map stock market interactions to spin models to recover their hierarchical structure using a simulated annealing based Super-Paramagnetic Clustering (SPC) algorithm. This is directly compared to a modified implementation of a maximum likelihood approach to fast-Super-Paramagnetic Clustering …
-
An investigation of precision and scaling issues in nuclear spin and trapped-ion quantum simulators
… of which motivate the experiments with nuclear spins and trapped ions presented in this thesis. The first challenge is determining the bounds on the precision of quantities that are calculated using a digital quantum simulator. As a specific example, we use a three-qubit nuclear spin system to …
-
Molecular Optimization for Classical and Quantum Condensed Phase Systems
… systems. We start with phenomenological spin models on a lattice and turn our attention to atomistic interfaces including aqueous electrolyte-electrode and polymer-protein composite. We discuss proficient schemes to implement and process our molecular simulations, allowing us to elucidate …
-
Dynamic weakening and trained memory in avalanche dynamics from high-entropy alloys to neurons and spin systems
… and crystalline solids to neuronal networks and spin models. Despite differences in microscopic mechanisms, these 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 …
-
Controlling exciton dimensionality in novel transition-metal dichalcogenide platforms
… Broken inversion symmetry, along with strong spin-orbit interaction, leads to coupling of the spin and valley degrees of freedom, allowing for valley-selective optical transitions. First, I confine long-lived interlayer excitons in WSe<sub>2</sub>/WS<sub>2</sub> heterobilayers to zero …
-
Computational Hardness in Random Optimization Problems from the Overlap Gap Property
… on the problems of random k-SAT and mean-field spin glasses. Our results are: • It is known that random k-SAT has a satisfying assignment with high probability up to clause density [formula], while the best known algorithm (Fix) finds a satisfying assignment up to clause density [formula]. We …
-
QUANTUM SIMULATION OF BOSONIC SYSTEM AND APPLICATION OF MACHINE LEARNING
… of generalized bosons include boson pairs and spins. We consider the analogue of the boson sampling task for these particles and observe that its output probabilities are still given by permanents, so the results regarding the difficulty of sampling carry over directly. Finally, we propose …
-
Spin Dynamics in a Tunable Heisenberg Magnet Realized with Ultracold Atoms
Spin is the elementary unit of magnetism. The interactions between many spins give a material its magnetic properties. This thesis focusses on one of the simplest magnetic materials: A one-dimensional chain of spins with tunable nearest-neighbor interactions. This system is described by the …
Page 1 of 2