Superconductor-based quantum information processing (S19)

Superconductor-based quantum information processing (Theory Seminar)

Dr. Amin Hosseinkhani

Contents

The physical properties of superconductors make them very attractive candidates for encoding fragile quantum information. In particular, superconductivity provides ultralow energy dissipation that together with the non-linearity of Josephson junctions enables us to make qubits. Superconducting qubits are nowadays one of the most promising candidates for quantum information processing; long coherence-time, high fidelity and short gate-operation-time of these types of qubits have convinced pioneer technology companies such as IBM or Google to invest on the physical realization of quantum computation using superconductor qubits. In this seminar course, we will briefly review some of the key aspects of superconductivity and then study different types of superconducting qubits, their coherence properties, and coupling schemes.

• Seminar im ZEuS

Topics

• Characterizing qubit coherence times
• Microscopics: BSC theory, Josephson junction
• Cooper-pair-box, phase and flux qubit
• Transmon and Fluxonium qubits
• Superconducting quasiparticle excitations: An intrinsic decoherence channel
• Protecting qubits form quasiparticles: Vortices, normal metals, pulse injection
• Multiqubit devices: Capacitive and inductive coupling
• Coupling qubits to resonators, circuit QED

Literature

• A. Zagoskin, Theory and Design of Quantum Coherent Structures (Cambridge University Press)
• Selection of original publications.