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Ramona Wolf

Publications and source records attributed to Ramona Wolf.

20 records · Page 2Linked to original sources

Entanglement detection by violations of noisy uncertainty relations: A proof of principle

It is well-known that the violation of a local uncertainty relation can be used as an indicator for the presence of entanglement. Unfortunately, the practical use of these non-linear witnesses has been limited to few special cases in the past. However, new methods for computing uncertainty bounds became available. Here we report on an experimental implementation of uncertainty-based entanglement witnesses, benchmarked in a regime dominated by strong local noise. We combine the new computational method with a local noise tomography in order to design noise-adapted entanglement witnesses. This proof-of-principle experiment shows that quantum noise can be successfully handled by a fully quantum model in order to enhance entanglement detection efficiencies.

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Quantum Key Distribution in the Non-Asymptotic Regime

This is a Bachelor's thesis on quantum key distribution in the non-asymptotic regime submitted to the Leibniz Universität Hannover, Germany. It deals with the question how to generate a key to encrypt messages between two honest parties that an eavesdropper does not gain any information about. The purpose of this thesis is to give an overview over the current state of the prepare and measure quantum key distribution protocol and its security proof with a specific focus on the non-asymptotic case. Therefore, we present the different steps of the protocol and retrace them with the help of the BB84-protocol. Afterwards, the security proof of this protocol is introduced and in the end, we have a closer look at the quantum capacity and calculate it for the amplitude damping channel.

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