Sökning: "superconducting qubits"

Visar resultat 16 - 20 av 33 avhandlingar innehållade orden superconducting qubits.

  1. 16. 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

  3. 17. Building a Bosonic Microwave Qubit

    Författare :Marina Kudra; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 3D cavity; qubit; cubic phase state; continuous variable; circuit QED; bosonic codes; GKP-state; superconducting circuits;

    Sammanfattning : Superconducting circuits is a promising platform for quantum computing. Quantum information is usually stored in discrete two-level qubits e.g. in transmon qubits. LÄS MER

  4. 18. 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

  5. 19. The quantum approximate optimization algorithm: optimization problems and implementations

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

    Sammanfattning : 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. LÄS MER

  7. 20. Degenerate and nondegenerate Josephson parametric oscillators for quantum information applications

    Författare :Andreas Bengtsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum information; superconducting circuits; multimode; circuit quantum electrodynamics; SQUID; Parametric oscillations;

    Sammanfattning : Parametric oscillations are well studied phenomena, with applications in amplification, quantum optics, and quantum information processing. They can occur as a parameter of a system, such as the resonant frequency, is being modulated or “pumped” by an external field. LÄS MER