Two-Qubit State Tomography using a Joint Dispersive Read-Out

Abstract

Quantum state tomography is an important tool in quantum information science for complete characterization of multi-qubit states and their correlations. Here we report a method to perform a joint simultaneous read-out of two superconducting qubits dispersively coupled to the same mode of a microwave transmission line resonator. The non-linear dependence of the resonator transmission on the qubit state dependent cavity frequency allows us to extract the full two-qubit correlations without the need for single shot read-out of individual qubits. We employ standard tomographic techniques to reconstruct the density matrix of two-qubit quantum states.

4 pages, 4 figures, version with high resolution figures available at http://qudev.ethz.ch/content/science/PubsPapers.html

References in corpus (2)

• Charge insensitive qubit design derived from the Cooper pair box
• Coupling Superconducting Qubits via a Cavity Bus

Cited by in corpus (5)

• Demonstration of Two-Qubit Algorithms with a Superconducting Quantum Processor
• Using Sideband Transitions for Two-Qubit Operations in Superconducting Circuits
• Quantum synchronization and entanglement of two qubits coupled to a driven dissipative resonator
• Dynamics of dispersive single qubit read-out in circuit quantum electrodynamics
• Proposal for generating and detecting multi-qubit GHZ states in circuit QED