Search for dissertations about: "Quantum method"

Showing result 1 - 5 of 390 swedish dissertations containing the words Quantum method.

2. 1. A quantum for a quantum : Quantum simulators in exotic lattices

   Author : Pil Maria Saugmann; Jonas Larson; André Eckardt; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; quantum physics; condensed matter physics; quantum optics; optical lattices. Fock state lattices; exotic lattices; frustration; Theoretical Physics; teoretisk fysik;

   Abstract : This thesis centers on how to use exotic lattices in different ways to design potential quantum simulators. These exotic lattices are either real physical objects in the form of ultra cold atoms in  bipartite optical lattice systems or lattice models revealed in state space. READ MORE

4. 2. On the role of the electron-electron interaction in two-dimensional quantum dots and rings

   Author : Erik Waltersson; Eva Lindroth; Stephanie Reimann; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; quantum dot; quantum ring; quantum dot molecule; electronic structure; two-dimensional; many-body physics; many-body perturbation theory; coupled cluster; coupled cluster singles and doubles; quantum logical gates; quantum computing; quantum control; quantum control algorithm; Electronic structure; Elektronstruktur; fysik; Physics;

   Abstract : Many-Body Perturbation Theory is put to test as a method for reliable calculations of the electron-electron interaction in two-dimensional quantum dots. We show that second order correlation gives qualitative agreement with experiments on a level which was not found within the Hartree-Fock description. READ MORE

5. 3. Machine learning for quantum information and computing

   Author : Shahnawaz Ahmed; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; quantum machine learning; quantum process tomography; quantum information; Machine learning; generative neural networks; variational quantum algorithms; quantum state tomography; optimization; quantum computing; Bayesian estimation;

   Abstract : This compilation thesis explores the merger of machine learning, quantum information, and computing. Inspired by the successes of neural networks and gradient-based learning, the thesis explores how such ideas can be adapted to tackle complex problems that arise during the modeling and control of quantum systems, such as quantum tomography with noisy data or optimizing quantum operations, by incorporating physics-based constraints. READ MORE

6. 4. Quantum Dynamics of Molecular Systems and Guided Matter Waves

   Author : Mauritz Andersson; Tamar Seideman; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; quantum dynamics; femtosecond spectroscopy; photoelectron spectroscopy; resonances; nonadiabatic interaction; coherent state representation; adaptive numerical method; Kvantkemi; Quantum chemistry; Kvantkemi; Quantum Chemistry; kvantkemi;

   Abstract : Quantum dynamics is the study of time-dependent phenomena in fundamental processes of atomic and molecular systems. This thesis focuses on systems where nature reveals its quantum aspect; e.g. in vibrational resonance structures, in wave packet revivals and in matter wave interferometry. READ MORE

7. 5. Modelling of Quantum Transport in Nanostructures

   Author : Dan Csontos; Fasta tillståndets fysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; ballistic transport; quantum wire; quantum dot; resonant tunnelling; three-terminal; disorder; Physics; Fysik; Fysicumarkivet A:2002:Csontos; scattering matrix; quantum transport;

   Abstract : In this thesis, theoretical studies of the transport properties of three nanoscale systems: one-dimensional (1D) quantum wires (QWRs), zero-dimensional (0D), laterally confined, double-barrier resonant tunnelling structures (DBRTSs) and three-terminal ballistic junctions (TBJs), have been performed. In the first part of the thesis, an overview of the realization and properties of such systems is given along with a description of modelling tools used in the calculations. READ MORE