Efficient amplification of photonic qubits by optimal quantum cloning

0436684 - FZÚ 2015 RIV US eng J - Journal Article
Bartkiewicz, K. - Černoch, A. - Lemr, K. - Soubusta, Jan - Stobińska, M.
Efficient amplification of photonic qubits by optimal quantum cloning.
Physical Review. A. Roč. 89, č. 6 (2014), "062322-1"-"062322-10". ISSN 1050-2947
Institutional support: RVO:68378271
Keywords : optimal quantum cloning * cryptography * qubit * phase-independent quantum amplifier
Subject RIV: BH - Optics, Masers, Lasers
Impact factor: 2.808, year: 2014

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. Sangouard, Phys. Rev. Lett. 105, 070501 (2010)]. It employs the multifunctional cloner in the 1 -> 2 copying regime, capable of providing approximate copies of qubits given by various probability distributions, and is optimized for distributions with axial symmetry. Direct applications of the proposed solution are possible in quantum technologies, doubling the range where quantum information is coherently broadcast. It also outperforms natural nonlinear amplifiers that use stimulated emission in bulk nonlinear materials. We consider the amplifier to be an important tool for amplifying quantum information sent via quantum channels with phase-independent damping.
Permanent Link: http://hdl.handle.net/11104/0240357