98 citations · 1.2k across the 60 of their papers we have counts for
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Efficient Amplification of Photonic Qubits by Optimal Quantum Cloning
Karol Bartkiewicz, Antonín Černoch, Karel Lemr +2
We demonstrate that a phase-independent quantum amplifier of a polarization qubit is a complementary amplifier of the heralded qubit amplifier [N. Gisin, S. Pironio and N. Sangouar…
State-dependent linear-optical qubit amplifier
Karol Bartkiewicz, Antonín Černoch, Karel Lemr
We propose a linear-optical setup for heralded qubit amplification with tunable output qubit fidelity. We study its success probability as a function of output qubit fidelity showi…
Direct method for measuring of purity, superfidelity, and subfidelity of photonic two-qubit mixed states
Karol Bartkiewicz, Karel Lemr, Adam Miranowicz
The Uhlmann-Jozsa fidelity (or, equivalently, the Bures distance) is a basic concept of quantum communication and quantum information, which however is very difficult to measure ef…
Entanglement estimation from Bell inequality violation
Karol Bartkiewicz, Bohdan Horst, Karel Lemr +1
It is well known that the violation of Bell's inequality in the form given by Clauser, Horne, Shimony, and Holt (CHSH) in two-qubit systems requires entanglement, but not vice vers…
Entanglement-based linear-optical qubit amplifier
Evan Meyer-Scott, Marek Bula, Karol Bartkiewicz +4
We propose a linear-optical scheme for an efficient amplification of a photonic qubit based on interaction of the signal mode with a pair of entangled ancillae. In contrast to a pr…
Resource-efficient linear-optical quantum router
Karel Lemr, Karol Bartkiewicz, Antonín Černoch +1
All-linear-optical scheme for fully featured quantum router is presented. This device directs the signal photonic qubit according to the state of one control photonic qubit. In the…