Sökning: "ground-state cooling"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden ground-state cooling.

1. 1. Electronic Control of Flexural Nanowire Vibrations

   Författare :Fabio Santandrea; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanoelectromechanical systems; Carbon nanotubes; Coulomb blockade; Shuttle instability; Ground-state cooling;

   Sammanfattning : “Nanoelectromechanical systems” (NEMS) are nanometer-sized mechanical structures coupled to electronic devices of comparable size. The coupling between mechanical and electronic degrees of freedom, combined with their mesoscopic size, provide these systemswith some unique properties that make them interesting from both the fundamental and technological point of view. LÄS MER

3. 2. Mesoscopic phenomena in the electromechanics of suspended nanowires

   Författare :Gustav Sonne; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanoelectromechanical systems; Ground-state cooling; Superconducting weak links; Carbon nanotubes; Non-linear resonance;

   Sammanfattning : Over the last two decades nanotechnology has been a very active field of scientific research, both from fundamental perspectives as well as for applications in technology and consumer goods. In this thesis, theoretical work on quantum mechanical effects on charge transport in nanoelectromechanical systems is presented. LÄS MER

4. 3. Electromechanical Phenomena in Superconducting and Normal Nanostructures

   Författare :Milton Eduardo Peña-Aza; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanoelectromechanical systems; nanoelectromechanical Josephson junctions; metallic carbon nanotubes; ground-state cooling; chaos;

   Sammanfattning : This thesis summarizes a series of theoretical studies on the electromechanical properties of nanostructures made of superconducting and/or metallic elements. The first part of the work is devoted to the analysis of the interactions between the electronic and mechanical degrees of freedom in suspended nanowires. LÄS MER

5. 4. Cooling of a Suspended Nanowire by an ac Josephson current

   Författare :Milton Eduardo Peña-Aza; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanoelectromechanical systems; nanowire; metallic carbon nanotubes; quantum ground state cooling of nanomechanical resonators; superconduting weak links; nanoelectromechanical Josephson junction;

   Sammanfattning : Nanoelectromechanical systems have been used for the exploration of the quantum limit of mechanical motion. There is hope that the quest for the quantum regime of these systems will shed light on fundamental questions in physics and lead to new quantum technologies. LÄS MER

7. 5. Ultrafast Dynamics in Ground and Excited States of Porphyrin Molecules

   Författare :Peter Martinsson; Kemisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; intra- and intermolecular dynamics.; Zn-porphyrin; bacteriochlorophyll a; chlorophyll b; Femtosecond transient absorption spectroscopy; chlorophyll a; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : This thesis describes inter and intramolecular dynamics in porphyrin molecules. To create a basis for understanding the energy and electron transfer processes in photosynthesis, the ultrafast dynamics of monomeric chlorophyll a, chlorophyll b and bacteriochlorophyll a were studied with ultrashort laser pulses. LÄS MER