title: Quantum Steering Inequality with Tolerance for Measurement-Setting Errors: Experimentally Feasible Signature of Unbounded Violation.
abstract: Quantum steering is a relatively simple test for proving that the values of quantum-mechanical measurement outcomes come into being only in the act of measurement. By exploiting quantum correlations, Alice can influence-steer-Bob's physical system in a way that is impossible in classical mechanics, as shown by the violation of steering inequalities. Demonstrating this and similar quantum effects for systems of increasing size, approaching even the classical limit, is a long-standing challenging problem. Here, we prove an experimentally feasible unbounded violation of a steering inequality. We derive its universal form where tolerance for measurement-setting errors is explicitly built in by means of the Deutsch-Maassen-Uffink entropic uncertainty relation. Then, generalizing the mutual unbiasedness, we apply the inequality to the multisinglet and multiparticle bipartite Bell state. However, the method is general and opens the possibility of employing multiparticle bipartite steering for randomness certification and development of quantum technologies, e.g., random access codes.
authors.affiliation: Institute of Theoretical Physics and Astrophysics, University of Gdańsk, ulica Wita Stwosza 57, 80-952 Gdańsk, Poland.|National Quantum Information Center of Gdańsk, ulica Władysława Andersa 27, 81-824 Sopot, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Rutkowski
authors.affiliation: Institute of Theoretical Physics and Astrophysics, University of Gdańsk, ulica Wita Stwosza 57, 80-952 Gdańsk, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Buraczewski
authors.affiliation: National Quantum Information Center of Gdańsk, ulica Władysława Andersa 27, 81-824 Sopot, Poland.|Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, ulica Gabriela Narutowicza 11/12, 80-233 Gdańsk, Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Horodecki
authors.affiliation: Institute of Theoretical Physics and Astrophysics, University of Gdańsk, ulica Wita Stwosza 57, 80-952 Gdańsk, Poland.|Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Stobińska