Publications (40)
Iterations of nonlinear entanglement witnesses
Tobias Moroder, Otfried Gühne, Norbert Lütkenhaus
We describe a generic way to improve a given linear entanglement witness by a quadratic, nonlinear term. This method can be iterated, leading to a whole sequence of nonlinear witne…
Effect of detector dead-times on the security evaluation of differential-phase-shift quantum key distribution against sequential attacks
Marcos Curty, Kiyoshi Tamaki, Tobias Moroder
We investigate limitations imposed by detector dead-times on the performance of sequential attacks against a differential-phase-shift (DPS) quantum key distribution (QKD) protocol…
Upper bound on the secret key rate distillable from effective quantum correlations with imperfect detectors
Tobias Moroder, Marcos Curty, Norbert Lütkenhaus
We provide a simple method to obtain an upper bound on the secret key rate that is particularly suited to analyze practical realizations of quantum key distribution protocols with…
Calibration robust entanglement detection beyond Bell inequalities
Tobias Moroder, Oleg Gittsovich
In its vast majority entanglement verification is examined either in the complete characterized or totally device independent scenario. The assumptions imposed by these extreme cas…
Analysing multiparticle quantum states
Otfried Gühne, Matthias Kleinmann, Tobias Moroder
The analysis of multiparticle quantum states is a central problem in quantum information processing. This task poses several challenges for experimenters and theoreticians. We give…
Experimental Comparison of Efficient Tomography Schemes for a Six-Qubit State
Christian Schwemmer, Geza Toth, Alexander Niggebaum +4
Quantum state tomography suffers from the measurement effort increasing exponentially with the number of qubits. Here, we demonstrate permutationally invariant tomography for which…