Search for dissertations about: "variational states"

Showing result 11 - 15 of 19 swedish dissertations containing the words variational states.

  2. 11. The one-dimensional Kondo Lattice in the Majorana Fermion representation

    Author : Matteo Bazzanella; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Majorana fermions; kondo lattice; path integral; spin-selective kondo insulator;

    Abstract : This thesis analyses the possibilities offered by the representation of quantum mechanical operators in terms of Majorana fermions. These objects can be imagined as algebraic constituents of the fermionic degrees of freedom, allowing for a different representation of many Hamiltonians. READ MORE

  4. 12. The quantum approximate optimization algorithm: optimization problems and implementations

    Author : Pontus Vikstål; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Quantum approximate optimization algorithm; quantum computing; error mitigation; cat qubits;

    Abstract : This thesis explores the Quantum Approximate Optimization Algorithm (QAOA), a hybrid classical-quantum algorithm designed to solve combinatorial optimization problems. The goal of this algorithm is to iteratively optimize a variational state to approximate the ground state of a cost Hamiltonian that encodes a combinatorial optimization problem. READ MORE

  5. 13. The Finite Difference Methods for Multi-phase Free Boundary Problems

    Author : Avetik Arakelyan; Henrik Shahgholian; John W. Barrett; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; MATHEMATICS; MATEMATIK;

    Abstract : This thesis consist of an introduction and four research papers concerning numerical analysis for a certain class of free boundary problems. Paper I is devoted to the numerical analysis of the so-called two-phase membrane problem. Projected Gauss-Seidel method is constructed. READ MORE

  6. 14. Transfer-Aware Kernels, Priors and Latent Spaces from Simulation to Real Robots

    Author : Rika Antonova; Danica Kragic; Jens Kober; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Computer Science; Datalogi;

    Abstract : Consider challenging sim-to-real cases lacking high-fidelity simulators and allowing only 10-20 hardware trials. This work shows that even imprecise simulation can be beneficial if used to build transfer-aware representations. READ MORE

  7. 15. Electrical and Optical Properties of AlGaAs/GaAs Aperiodic Superlattices and Resonant Tunneling Diodes. Theory, Design and Applications

    Author : Simon Mang Cao; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; exciton-assisted transport; miniband; high-speed quantum electronics; optical properties; ultrafast optoelectronics; field-induced transport; irregular superlattices; nanometer-scale heterostructures; laser diodes; resonant tunneling;

    Abstract : The objective of the work presented in this thesis is to study quantum transport and optical properties of aperiodic superlattices and resonant tunneling diodes using III-V semiconductor heterostructures grown by molecular beam epitaxy. The study follows a procedure of theoretical modeling, computer-aided design and simulation, sample growth, and measurements. READ MORE