Proposal for Implementing Device-Independent Quantum Key Distribution Based on a Heralded Qubit Amplifier

In device-independent quantum key distribution (DIQKD), the violation of a Bell inequality is exploited to establish a shared key that is secure independently of the internal workings of the QKD devices. An experimental implementation of DIQKD, however, is still awaited, since hitherto all optical Bell tests are subject to the detection loophole, making the protocol unsecured. In particular, photon losses in the quantum channel represent a fundamental limitation for DIQKD. Here we introduce a heralded qubit amplifier based on single-photon sources and linear optics that provides a realistic solution to overcome the problem of channel losses in Bell tests.

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Electric-field-induced coherent coupling of the exciton states in a single quantum dot

The signature of coherent coupling between two quantum states is an anticrossing in their energies as one is swept through the other. In single semiconductor quantum dots containing an electron–hole pair the eigenstates form a two-level system that can be used to demonstrate quantum effects in the solid state, but in all previous work these states were independent. Here we describe a technique to control the energetic splitting of these states using a vertical electric field, facilitating the observation of coherent coupling between them.

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Prof. Christine Silberhorn received Gottfried Wilhelm Leibniz Prize

Prof. Christine Silberhorn from Universität Paderborn, a partner in Q-ESSENCE consortium, received the prestigious Gottfried Wilhelm Leibniz Prize.
Prof. Silberhorn leads the integrated quantum optics group in the Department of Physics.
Congratulations!

Project & realization: Pixels United.
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