Quantum steering inequality with tolerance for measurement-setting-errors: experimentally feasible signature of unbounded violation

Understand

Quantum steering is a relatively simple test for quantumness of correlations, 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 inaccessible in classical world, leading to violation of some 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 provide experimentally feasible signature of unbounded violation of a steering inequality.