Experimental EPR-Steering of Bell-local States

Understand

Entanglement is the defining feature of quantum mechanics, and understanding the phenomenon is essential at the foundational level and for future progress in quantum technology.

• The concept of steering was introduced in 1935 by Schr\"odinger as a generalization of the Einstein-Podolsky-Rosen (EPR) paradox.
• Surprisingly, it has only recently been formalized as a quantum information task with arbitrary bipartite states and measurements, for which the existence of entanglement is necessary but not sufficient.
• Previous experiments in this area have been restricted to the approach of Reid [PRA 40, 913], which followed the original EPR argument in considering only two different measurement settings per side.