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arXiv · 0812.2485

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

S. Filipp·P. Maurer·P. J. Leek·M. Baur·R. Bianchetti·J. M. Fink·M. Göppl·L. Steffen·J. M. Gambetta·A. Blais·A. Wallraff
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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.

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S. Filipp, P. Maurer, P. J. Leek, M. Baur, R. Bianchetti, J. M. Fink, M. Göppl, L. Steffen, J. M. Gambetta, A. Blais, A. Wallraff. 2008-12-15. Two-Qubit State Tomography using a Joint Dispersive Read-Out. https://doi.org/10.1103/physrevlett.102.200402

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