Coherence of a Josephson phase qubit under partial-collapse measurement

Abstract

We discuss quantum evolution of a decaying state in relation to a recent experiment of Katz et al. Based on exact analytical and numerical solutions of a simple model, we identify a regime where qubit retains coherence over a finite time interval independently of the rates of three competing decoherence processes. In this regime, the quantum decay process can be continuously monitored via a ``weak'' measurement without affecting the qubit coherence.

4p., 2eps figures

References in corpus (1)

• Interaction-free measurements with superconducting qubits

Cited by in corpus (2)

• Analysis of Bell inequality violation in superconducting qubits
• Quantum efficiency of binary-outcome detectors of solid-state qubits