Experimental observation of Einstein-Podolsky-Rosen steering via entanglement detection

Abstract

The Einstein-Podolsky-Rosen (EPR) steering is an intermediate quantum nonlocality between entanglement and Bell nonlocality, which plays an important role in quantum information processing tasks. In the past few years, the investigations concerning EPR steering have been demonstrated in a series of experiments. However, these studies rely on the relevant steering inequalities and the choices of measurement settings. Here, we experimentally verify the EPR steering via entanglement detection without using any steering inequality and measurement setting. By constructing two new states from a two-qubit target state, we observe the EPR steering by detecting the entanglement of these new states. The results show that the entanglement of the newly constructed states can be regarded as a new kind of steering witness for target states. Compared to the results of Xiao et al. [Phys. Rev. Lett. 118, 140404 (2017)], we find that the ability of detecting EPR steering in our scenario is stronger than two-setting projective measurements, which can observe more steerable states. Hence, our demonstrations can deepen the understanding of the connection between the EPR steering and entanglement. arXiv:1912.05755v2 [quant-ph]

Asymmetric steerability of quantum equilibrium and nonequilibrium steady states through entanglement detection

“…The entanglement-detection steering criterion can distinguish the asymmetric steerability based on the test on some types of two-qubit states [18,41]. Recent experiments show that it is also superior than some other steering criterion which can also reveal the asymmetric steerability [18].…”

“…The entanglement-detection steering criterion can distinguish the asymmetric steerability based on the test on some types of two-qubit states [18,41]. Recent experiments show that it is also superior than some other steering criterion which can also reveal the asymmetric steerability [18]. We also find that the steerability of the system in this paper revealed by the entanglement-detection steering criterion, covers the linear steering criteria up to six measurements [15], where the latter also fails to capture the asymmetric steerability.…”

“…The detuning is set as (a) ∆ε = 0.1ε; (b)(c) ∆ε = 1.6ε. [18,49]. In our two-qubit model, suppose that the four eigenstates |00 AB , |11 AB and |ψ ± (θ) AB have the probabilities p 00 , p 11 and p ± .…”

“…See [7] for more criteria based on different aspects. Numerous experiments have demonstrated the steerability of two-qubit states, based on different criteria, in the last ten years [15][16][17][18][19].…”

Constraint Relation Between Steerability and Concurrence for Two‐Qubit States

“…Recently, steering has attracted extensive attentions and has revealed many advantages in quantum information applications. [ 4–9 ] Costa et al. proposed a measure of steering that is based on the maximal violation of the line steering inequality in two‐ and three‐measurement scenarios.…”