Observation of measurement-induced entanglement and quantum trajectories of remote superconducting qubits.
The creation of a quantum network requires the distribution of coherent information across macroscopic distances. We demonstrate the entanglement of two superconducting qubits, separated by more than a meter of coaxial cable, by designing a joint measurement that probabilistically projects onto an entangled state. By using a continuous measurement scheme, we are further able to observe single quantum trajectories of the joint two-qubit state, confirming the validity of the quantum Bayesian formalism for a cascaded system. Our results allow us to resolve the dynamics of continuous projection onto the entangled manifold, in quantitative agreement with theory.
Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA.
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Roch
Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA.
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Schwartz
Department of Chemistry, University of California, Berkeley, California 94720, USA.
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Motzoi
Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA.
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Macklin
Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai 400005, India.
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Vijay
Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA.
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Eddins
Department of Electrical Engineering, University of California, Riverside, California 92521, USA.
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Korotkov
Department of Chemistry, University of California, Berkeley, California 94720, USA.
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Whaley
Scalable and Secure Systems Research (08961), Sandia National Laboratories, Livermore, California 94550, USA.
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Sarovar
Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA.
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Siddiqi