98 citations · 1.2k across the 60 of their papers we have counts for
6 papers · 2 filters
Direct method for measuring and witnessing quantum entanglement of arbitrary two-qubit states through Hong-Ou-Mandel interference
Karol Bartkiewicz, Grzegorz Chimczak, Karel Lemr
We describe a direct method for experimental determination of the negativity of an arbitrary two-qubit state with 11 measurements performed on multiple copies of the two-qubit syst…
Bell nonlocality and fully-entangled fraction measured in an entanglement-swapping device without quantum state tomography
Karol Bartkiewicz, Karel Lemr, Antonín Černoch +1
We demonstrate an efficient experimental procedure based on entanglement swapping to determine the Bell nonlocality measure of Horodecki et al. [Phys. Lett. A 200, 340 (1995)] and…
Measuring evolution of a photon in an interferometer with spectrally-resolved modes
Marek Bula, Karol Bartkiewicz, Antonín Černoch +4
In the year 2013, Danan et al. published a paper [Phys. Rev. Lett. 111, 240402 (2013)] demonstrating a counterintuitive behavior of photons in nested Mach-Zehnder interferometers.…
Experimental quantum forgery of quantum optical money
Karol Bartkiewicz, Antonín Černoch, Grzegorz Chimczak +3
Unknown quantum information cannot be perfectly copied (cloned). This statement is the bedrock of quantum technologies and quantum cryptography, including the seminal scheme of Wie…
Experimental temporal quantum steering
Karol Bartkiewicz, Antonín Černoch, Karel Lemr +2
Temporal steering is a form of temporal correlation between the initial and final state of a quantum system. It is a temporal analogue of the famous Einstein-Podolsky-Rosen (spatia…
Experimental measurement of the collectibility of two-qubit states
Karel Lemr, Karol Bartkiewicz, Antonín Černoch
We present a proof-of-principle experiment demonstrating measurement of the collectibility, a nonlinear entanglement witness proposed by Rudnicki et al. [Phys. Rev. Lett. 107, 1505…