Multiqubit entanglement due to quantum gravity

Alexander Streltsov

Hyuk‐Jae Lee, Sung Dahm Oh, Doyeol Ahn

We present an entanglement criterion for multiqubits by using the quantum correlation tensors which rely on the expectation values of the Pauli operators for a multiqubit state. Our criterion explains not only the total entanglement of the system but also the partial entanglement in subsystems. It shows that we have to consider the subsystem entanglements in order to obtain the full description for multiqubit entanglements. Furthermore, we offer an extension of the entanglement to multiqudits.

Jeong San Kim

We provide strong evidence for the strong monogamy inequality of multiqubit entanglement recently proposed [B. Regula et al., Phys. Rev. Lett. 113, 110501 (2014)]. We consider a large class of multiqubit generalized $W$-class states and analytically show that the strong monogamy inequality of multiqubit entanglement is saturated by this class of states.

Ian Lawson

Nicolas Gisin

Eduardo Martín-Martínez, Tales Rick Perche

We revisit the Bose-Marletto-Vedral (BMV) tabletop experimental proposal---which aims to witness quantum gravity using gravity-mediated entanglement---analyzing the role of locality in the experiment. We first carry out a fully quantum modeling of the interaction of matter and gravity and then show in what way gravity-mediated entanglement in the BMV experiment could be accounted for without appealing to quantum degrees of freedom of the gravitational field. We discuss what assumptions are needed in order to interpret the current BMV experiment proposals as a proof of quantum gravity, and also identify the modifications that a BMV-like experiment could have in order to serve as proof of quantum gravity without having to assume the existence of local mediators in the gravitational field.