Analysis of measurement errors for a superconducting phase qubit

Abstract

We analyze several mechanisms leading to errors in a course of measurement of a superconducting flux-biased phase qubit. Insufficiently long measurement pulse may lead to nonadiabatic transitions between qubit states $|1>$ and $|0>$, before tunneling through a reduced barrier is supposed to distinguish the qubit states. Finite (though large) ratio of tunneling rates for these states leads to incomplete discrimination between $|1>$ and $|0>$. Insufficiently fast energy relaxation after the tunneling of state $|1>$ may cause the repopulation of the quantum well in which only the state $|0>$ is supposed to remain. We analyze these types of measurement errors using analytical approaches as well as numerical solution of the time-dependent Schrödinger equation.

14 pages, 14 figures

References in corpus (7)

• Approaching Unit Visibility for Control of a Superconducting Qubit with Dispersive Readout
• Mach-Zehnder Interferometry in a Strongly Driven Superconducting Qubit
• Dephasing of a superconducting qubit induced by photon noise
• State tomography of capacitively shunted phase qubits with high fidelity
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Cited by in corpus (9)

• Tunable-Cavity QED with Phase Qubits
• Multilevel effects in the Rabi oscillations of a Josephson phase qubit
• Theory of measurement crosstalk in superconducting phase qubits
• Phase-space theory for dispersive detectors of superconducting qubits
• Nanosecond quantum state detection in a current biased dc SQUID
• Mesoscopic Shelving Readout of Superconducting Qubits in Circuit QED
• Optimal fast single pulse readout of qubits
• Fine tuning of phase qubit parameters for optimization of fast single-pulse readout
• Transitional dynamics of a phase qubit-resonator system: requirements for fast readout of a phase qubit