Search for dissertations about: "geometric phase"

Showing result 1 - 5 of 68 swedish dissertations containing the words geometric phase.

2. 1. Quantal trajectories and geometric phase

   Author : Henrik Carlsen; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; Kvantkemi; Quantum chemistry; Kvantkemi; Quantum Chemistry; kvantkemi;

   Abstract : This thesis concerns the following topics: geometric phase in the context of Galilean invariance and quantum measurements, Rydberg states of hydrogen atoms, vibronic coupling in the E Ä e Jahn-Teller system and realism in quantum computations. In the analyses the de Broglie-Bohm pilot-wave formulation of quantummechanics is mainly used. READ MORE

4. 2. Crystallization of the superconducting phase in unconventional superconductors

   Author : Patric Holmvall; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; pattern formation; spontaneous symmetry breaking; Andreev bound states; mesoscopic superconductivity; phase crystals; thin superconducting films; phase transitions; non-local Ginzburg-Landau theory; time-reversal symmetry; flat bands; unconventional superconductivity; quasiclassical theory; translational symmetry; cuprates; inhomogeneous superconductivity;

   Abstract : Superconductivity is a macroscopic quantum phenomenon, in the sense that a macroscopic number of electrons form a pair condensate, that occupies a single ground state. The electrons in this state are phase-coherent, breaking global U (1)-symmetry, and spatial variations of the phase imply superflows that usually cost kinetic energy, resulting in a uniform and rigid phase. READ MORE

5. 3. Quantum Holonomy for Many-Body Systems and Quantum Computation

   Author : Vahid Azimi Mousolou; Erik Sjöqvist; Rosario Fazio; Linnéuniversitetet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Quantum holonomy; geometric phase; quantum correlations; quantum phase transitions; quantum computation; Natural Science; Naturvetenskap; Physics; Fysik;

   Abstract : The research of this Ph. D. thesis is in the field of Quantum Computation and Quantum Information. A key problem in this field is the fragile nature of quantum states. READ MORE

6. 4. Geometric and Topological Phases with Applications to Quantum Computation

   Author : Marie Ericsson; Ignacio Cirac; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; geometric phases; topological phases; quantum computation; mixed states; completely positive maps; Fysik; Physics; Fysik; fysik; Physics;

   Abstract : Quantum phenomena related to geometric and topological phases are investigated. The first results presented are theoretical extensions of these phases and related effects. Also experimental proposals to measure some of the described effects are outlined. READ MORE

7. 5. Quantum Holonomies : Concepts and Applications to Quantum Computing and Interferometry

   Author : David Kult; Erik Sjöqvist; Gunnar Björk; Barry Sanders; Uppsala universitet; []
   Keywords : Physics; Quantum Holonomy; Geometric Phase; Quantum Computation; Completely Positive Map; Mixed State; Interferometry; Fysik;

   Abstract : Quantum holonomies are investigated in different contexts.A geometric phase is proposed for decomposition dependent evolution, where each component of a given decomposition of a mixed state evolves independently. It is shown that this geometric phase only depends on the path traversed in the space of decompositions. READ MORE