Research Results

The following links contain short summaries of recently published papers.

C. Lang et al., Nat. Phys. 9, 345, published 05 May 2013

We present the very first measurement of the Hong-Ou-Mandel effect outside the domain of optical frequency photons. This genuinely quantum effect allows us to demonstrate the fundamental indistinguishability of single particles of light (photons) at microwave frequencies by measuring their coalescence into a photon pair at a beam splitter.

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A. Abdumalikov et al., Nature 496, 482, published 17 April 2013

Imagine, you plan for a Sundays hike along a splendid trail laid out in a figure-eight and you have to decide which of the two lobes you walk about first. Usually, it makes no difference and any choice leaves you afterwards in the same weary but contented state of mind. We have now demonstrated that in a quantum world you have to be more careful in your choice.

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C. Eichler et al., Phys. Rev. Lett. 109, 240501, published 10 Dec 2012 C. Eichler et al., Phys. Rev. A 86, 032106, published 10 Sept 2012

Propagating photons are ideal carriers for distributing entanglement between distant matter systems in a quantum network. Entanglement between photons and stationary qubits has thus far been exclusively studied at optical frequencies with single atoms or electron spins.

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J. A. Mlynek et al., Phys. Rev. A 86, 053838, published 30 Nov 2012

We have exploited the resonant interaction between three superconducting transmon-type qubits and a microwave transmission line resonator to show that a W-state can be generated with high efficiency in this system by harnessing its collective dynamics. Interestingly, our method also benefits from the √N-nonlinearity of the coupling strength between N qubits and a single field mode.

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G. Puebla-Hellmann, A. Wallraff, Appl. Phys. Lett. 101, 053108, 30 July 2012

Microwave circuits based on superconducting transmission lines can also be used to investigate electron transport through nanometer scale electronic devices based on single molecules or carbon nanotubes.

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