Sökning: "quantum vacuum"

Visar resultat 1 - 5 av 49 avhandlingar innehållade orden quantum vacuum.

1. 1. Quantum Coherence and Quantum-Vacuum Effects in Some Artificial Electromagnetic Media

   Författare :Jianqi Shen; Sailing He; Chris Phillips; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Quantum coherence; quantum vacuum; electromagnetically induced transparency; negative refractive index; artificial electromagnetic media; electric- and magnetic-dipole transitions; multilevel atomic vapors; transient evolution; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Sammanfattning : The author of this thesis concentrates his attention on quantum optical properties of some artificial electromagnetic media, such as quantum coherent atomic vapors (various multilevel electromagnetically induced transparency vapors) and negative refractive index materials, and suggests some possible ways to manipulate wave propagations inside the artificial electromagnetic materials based on quantum coherence and quantum vacuum effects. In Chapters 1 and 2, the author reviews the previous papers on quantum coherence as well as the relevant work such as electromagnetically induced transparency (EIT), atomic population trapping and their various applications. LÄS MER

3. 2. QED and collective effects in vacuum and plasmas

   Författare :Joakim Lundin; Mattias Marklund; Thomas Heinzl; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; QED; quantum electrodynamics; quantum plasmas; quantum vacuum; Plasma physics; Plasmafysik; fysik; Physics;

   Sammanfattning : The theory of quantum electrodynamics (QED) was born out of an attempt to merge Einsteins theory of special relativity and quantum mechanics. Einsteins energy/mass equivalence together with Heisenberg's uncertainty principle allows for particle pairs to be spontaneously created and annihilated in vacuum. LÄS MER

4. 3. Quantum optics with artificial atoms

   Författare :Anton Frisk Kockum; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; surface acoustic waves; transmon; circuit QED; photon detector; parity measurement; quantum stochastic calculus; Quantum optics; artificial atoms; quantum measurement;

   Sammanfattning : Quantum optics is the study of interaction between atoms and photons. In the eight papers of this thesis, we study a number of systems where artificial atoms (here, superconducting circuits emulating the level structure of an atom) enable us to either improve on known concepts or experiments from quantum optics with natural atoms, or to explore entirely new regimes which have not been possible to reach in such experiments. LÄS MER

5. 4. Quantum Optics and Waveguide Quantum Electrodynamics in Superconducting Circuits

   Författare :Emely Wiegand; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Quantum Optics; Circuit Quantum Electrodynamics; Waveguide Quantum Electrodynamics; Superconducting Qubits; Artificial Atoms;

   Sammanfattning : Waveguide circuit quantum electrodynamics (waveguide circuit QED) studies light-matter interaction with superconducting circuits in one dimension. In circuit QED, natural atoms are replaced by superconducting qubits consisting of a non-linear Josephson junction, resulting in an anharmonic energy spectrum just like real atoms. LÄS MER

7. 5. Quantum acoustics with superconducting circuits

   Författare :Gustav Andersson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; superconducting qubits; cluster states; SAW; two-level systems; circuit QED; giant atoms; two-mode squeezing; surface acoustic wave; quantum acoustics; hybrid quantum systems;

   Sammanfattning : The past 20 years has seen rapid developments in circuit quantum electrodynamics, where superconducting qubits and resonators are used to control and study quantum light-matter interaction at a fundamental level. The development of this field is strongly influenced by quantum information science and the prospect of realizing quantum computation, but also opens up opportunities for combinations of different physical systems and research areas. LÄS MER