Sökning: "quantum dissipation"

Visar resultat 6 - 10 av 31 avhandlingar innehållade orden quantum dissipation.

  1. 6. Time-dependent relaxation of charge and energy in electronic nanosystems

    Författare :Jens Schulenborg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; heat current; quantum dot; relaxation rate; rate detection; generalization of hermiticity; nonunitary dynamics; open quantum system; Coulomb charging energy; voltage switch; transient response; electronic nanosystem;

    Sammanfattning : The study of the dynamics of strongly confined, interacting open quantum systems has attracted great interest over the past years, due to potential applications in nanoelectronics, metrology as well as quantum information. Most recent experimental and theoretical research in this field has shifted attention towards electronic heat currents, recognizing their potential for practical purposes as well as for tests of fundamental theories, and also aiming to control the inevitable heat dissipation of any dynamically operated electronic device. LÄS MER

  3. 7. Superinductance and fluctuating two-level systems: Loss and noise in disordered and non-disordered superconducting quantum devices

    Författare :David Niepce; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Disordered Superconductors; Nanowire; Superinductor; Quantum information; Superconducting circuits; Superinductance; TLS; Two-level Systems;

    Sammanfattning : In this thesis, we first demonstrate that a disordered superconductor with high kinetic inductance can realise a microwave low-loss, non-dissipative circuit element with impedance greater than the quantum resistance. This element, known as a superinductor, can suppress the fluctuations of charge in a quantum circuit. LÄS MER

  4. 8. Fast-tunable resonators and quantum electrical circuits

    Författare :Martin Sandberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SEB; tunable; Sisyphus resistance; CPW; Resonator; SCB; qubit; circuit-QED; transmon; SQUID;

    Sammanfattning : In this thesis, measurements on superconducting electrical circuits that exhibit quantum mechanical effects are presented. Nonlinear superconducting circuits can be regarded as artificial atoms with energy spectra that can be engineered. The artificial atoms can be used as quantum bits for quantum computation. LÄS MER

  5. 9. Quantum transport and geometric integration for molecular systems

    Författare :Anders Odell; Anna Delin; Anders Niklasson; Michael Springborg; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; density functional theory; ab initio; first principles; electron transport; photoswitching; molecular dynamics; geometric integration; Condensed matter physics; Kondenserade materiens fysik; Computational physics; Beräkningsfysik;

    Sammanfattning : Molecular electronics is envisioned as a possible next step in device miniaturization. It is usually taken to mean the design and manufacturing of electronic devices and applications where organic molecules work as the fundamental functioning unit. LÄS MER

  7. 10. Fast dynamics and measurements of single-charge devices

    Författare :Fredrik Persson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; resonator; single-electron box; superconducting devices; decoherence; quantum capacitance; Sisyphus resistance; transmon; single-Cooper-pair box; qubit; rf-reflectometry;

    Sammanfattning : In this thesis we present measurements on several different devices, including the single-Cooper-pair box (SCB), the single-electron box, tunable superconducting resonators and so called transmon qubits.By exploiting the quantum capacitance of the SCB, its state was measured by embedding the box in a radio-frequency resonator. LÄS MER