Rescaling Interactions for Quantum Control
PHYSICAL REVIEW APPLIED 13:3 (2020) 34002
Abstract:
© 2020 American Physical Society. A powerful control method in experimental quantum computing is the use of spin echoes, employed to select a desired term in the system's internal Hamiltonian, while refocusing others. Here, we address a more general problem, describing a method to not only turn on and off particular interactions but also to rescale their strengths so that we can generate any desired effective internal Hamiltonian. We propose an algorithm based on linear programming for achieving time-optimal rescaling solutions in fully coupled systems of tens of qubits, which can be modified to obtain near-time-optimal solutions for rescaling systems with hundreds of qubits.Rescaling interactions for quantum control
Physical Review Applied American Physical Society 13:3 (2020) 034002
Abstract:
A powerful control method in experimental quantum computing is the use of spin echoes, employed to select a desired term in the system’s internal Hamiltonian, while refocusing others. Here, we address a more general problem, describing a method to not only turn on and off particular interactions but also to rescale their strengths so that we can generate any desired effective internal Hamiltonian. We propose an algorithm based on linear programming for achieving time-optimal rescaling solutions in fully coupled systems of tens of qubits, which can be modified to obtain near-time-optimal solutions for rescaling systems with hundreds of qubits.Development and characterization of a flux-pumped lumped element Josephson parametric amplifier
EPJ Web of Conferences EDP Sciences 198 (2019)
Abstract:
Josephson parametric amplification is a tool of paramount importance in circuit-QED especially for the quantum-noise-limited single-shot readout of superconducting qubits. We developed a Josephson parametric amplifier (JPA) based on a lumped-element LC resonator, in which the inductance L is composed by a geometric inductance and an array of 4 superconducting quantum interference devices (SQUIDs). We characterized the main figures of merit of the device, obtaining a −3 dB bandwidth BW = 15 MHz for a gain G = 21 dB and a 1 dB compression point P1dB = −115 dBm. The obtained results are promising for the future use of such JPA as the first stage of amplification for single-shot readout of superconducting qubits.Noise characterisation of a flux-pumped lumped-element josephson parametric amplifier using an SIS mixer
ISSTT 2019 - 30th International Symposium on Space Terahertz Technology, Proceedings Book (2019) 168
Multilayer Coaxial Superconducting Circuits with Integrated 3D Wiring
Optica Publishing Group (2019) f3b.1