Experimental device-independent verification of quantum steering

Abstract

Bell nonlocality between distant quantum systems---i.e., joint correlations which violate a Bell inequality---can be verified without trusting the measurement devices used, nor those performing the measurements. This leads to unconditionally secure protocols for quantum information tasks such as cryptographic key distribution. However, complete verification of Bell nonlocality requires high detection efficiencies, and is not robust to the typical transmission losses that occur in long distance applications. In contrast, quantum steering, a weaker form of quantum correlation, can be verified for arbitrarily low detection efficiencies and high losses. The cost is that current steering-verification protocols require complete trust in one of the measurement devices and its operator, allowing only one-sided secure key distribution. We present device-independent steering protocols that remove this need for trust, even when Bell nonlocality is not present. We experimentally demonstrate this principle for singlet states and states that do not violate a Bell inequality.

7 pages, 3 figures

References in corpus (9)

• Steering, Entanglement, Nonlocality, and the EPR Paradox
• Experimental criteria for steering and the Einstein-Podolsky-Rosen paradox
• Observation of one-way Einstein-Podolsky-Rosen steering
• Entanglement-enhanced measurement of a completely unknown phase
• Grothendieck's constant and local models for noisy entangled quantum states
• Measurement-Device-Independent Entanglement Witnesses for All Entangled Quantum States
• More efficient Bell inequalities for Werner states
• Implementation of a Measurement-Device-Independent Entanglement Witness
• Optimal Measurements for Tests of EPR-Steering with No Detection Loophole using Two-Qubit Werner States

Cited by in corpus (4)

• Einstein-Podolsky-Rosen steering measure for two-mode continuous variable states
• Einstein-Podolsky-Rosen steering and Bell nonlocality of two macroscopic mechanical oscillators in optomechanical systems
• Sharing quantum steering among multiple Alices and Bobs via a two-qubit Werner state
• Remotely preparing optical Schrödinger cat states via homodyne detection in nondegenerate triple-photon spontaneous downconversion