Sökning: "Quantum Computing"

Visar resultat 1 - 5 av 103 avhandlingar innehållade orden Quantum Computing.

1. 1. Quantum Holonomies : Concepts and Applications to Quantum Computing and Interferometry

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

   Sammanfattning : 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. LÄS MER

3. 2. Machine learning for quantum information and computing

   Författare :Shahnawaz Ahmed; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

4. 3. Open Quantum Systems : Effects in Interferometry, Quantum Computation, and Adiabatic Evolution

   Författare :Johan Åberg; Erik Sjöqvist; Sten Lunell; Vlatko Vedral; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Open Systems; Completely Positive Maps; Channels; Decoherence; Quantum Information; Quantum Computing; Adiabatic Approximation; Quantum Search; Time-Complexity; Fysik; Physics; Fysik;

   Sammanfattning : The effects of open system evolution on single particle interferometry, quantum computation, and the adiabatic approximation are investigated.Single particle interferometry: Three concepts concerning completely positive maps (CPMs) and trace preserving CPMs (channels), named subspace preserving (SP) CPMs, subspace local channels, and gluing of CPMs, are introduced. LÄS MER

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

   Författare :Erik Waltersson; Eva Lindroth; Stephanie Reimann; Stockholms universitet; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

7. 5. Realistic prospect for continuous variable quantum computing in circuit-QED

   Författare :Ingrid Strandberg; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Continuous variable quantum computing; quantum supremacy; quantum state engineering; negative Wigner function; quantum advantage;

   Sammanfattning : This licentiate thesis is an extended introduction to the appended papers, which pertain to finding quantum states that are useful for continuous variable quantum computing. The useful states are characterized by a negative Wigner function. LÄS MER