Transformed Dissipation in Superconducting Quantum Circuits

Abstract

Superconducting quantum circuits must be designed carefully to avoid dissipation from coupling to external control circuitry. Here we introduce the concept of current transformation to quantify coupling to the environment. We test this theory with an experimentally-determined impedance transformation of $\sim 10^5$ and find quantitative agreement better than a factor of 2 between this transformation and the reduced lifetime of a phase qubit coupled to a tunable transformer. Higher-order corrections from quantum fluctuations are also calculated with this theory, but found not to limit the qubit lifetime. We also illustrate how this simple connection between current and impedance transformation can be used to rule out dissipation sources in experimental qubit systems.

4 pages, 4 figures

References in corpus (6)

• Coupling Superconducting Qubits via a Cavity Bus
• Coherent quantum state storage and transfer between two phase qubits via a resonant cavity
• Decoherence of flux qubits due to 1/f flux noise
• Dephasing of a superconducting qubit induced by photon noise
• State tomography of capacitively shunted phase qubits with high fidelity
• Asymmetry and decoherence in a double-layer persistent-current qubit

Cited by in corpus (21)

• Controlling the spontaneous emission of a superconducting transmon qubit
• Circuit QED lattices: towards quantum simulation with superconducting circuits
• Fast Reset and Suppressing Spontaneous Emission of a Superconducting Qubit
• Measurement of the decay of Fock states in a superconducting quantum circuit
• Photon Shot Noise Dephasing in the Strong-Dispersive Limit of Circuit QED
• Quantum superposition of a single microwave photon in two different "colour" states
• Circuit QED and engineering charge based superconducting qubits
• Multiplexed dispersive readout of superconducting phase qubits
• Decoherence Dynamics of Complex Photon States in a Superconducting Circuit
• Nonequilibrium thermodynamics of erasure with superconducting flux logic
• Suppression of dephasing by qubit motion in superconducting circuits
• Tunable-Cavity QED with Phase Qubits
• Mechanism of generation of a Josephson phase shift by an Abrikosov vortex
• Phase qubits fabricated with trilayer junctions
• QND measurement of a superconducting qubit in the weakly projective regime
• Decoherence of floating qubits due to capacitive coupling
• Meissner transmon qubit - architecture and characterization
• Interferometric Purcell suppression of spontaneous emission in a superconducting qubit
• Controlling the energy gap of a tunable two-level system by ac drive
• Directional emission of a readout resonator for qubit measurement
• Computational modeling of decay and hybridization in superconducting circuits