Abstract
We characterize a pair of Cooper-pair boxes coupled with a fixed capacitor using spectroscopy and measurements of the ground-state quantum capacitance. We use the extracted parameters to estimate the concurrence or degree of entanglement between the two qubits. We also present a thorough demonstration of a multiplexed quantum capacitance measurement technique, which is in principle scalable to a large array of superconducting qubits.
- Received 16 September 2008
DOI:https://doi.org/10.1103/PhysRevB.79.014516
©2009 American Physical Society