A two-dimensional quantum walk driven by a single two-side coin

We study a two-dimensional quantum walk with only one walker alternatively walking along the horizontal and vertical directions driven by a single two-side coin.We find the analytical expressions of the first two moments of the walker’s position distribution in the long-time limit,which indicates that the variance of the position distribution grows quadratically with walking steps,showing a ballistic spreading typically for quantum walks.Besides,we analyze the correlation by calculating the quantum mutual information and the measurement-induced disturbance respectively as the outcome of the walk in one dimension is correlated to the other with the coin as a bridge.It is shown that the quantum correlation between walker spaces increases gradually with the walking steps.

Optical scheme to demonstrate state-independent quantum contextuality

The contradiction between classical and quantum physics can be identified through quantum contextuality, which does not need composite systems or spacelike separation. Contextuality is proven either by a logical contradiction between the noncontextuality hidden variable predictions and those of quantum mechanics or by the violation of noncontextual inequality. We propose an experimental scheme of state-independent contextual inequality derived from the Mermin proof of the Kochen–Specker(KS) theorem in eight-dimensional Hilbert space, which could be observed either in an individual system or in a composite system. We also show how to resolve the compatibility problems. Our scheme can be implemented in optical systems with current experiment techniques.

Distinct roles of two RDL GABA receptors in fipronil action in the diamondback moth (Plutella xylostella)

The phenylpyrazole insecticide fipronil blocks resistance to dieldrin(RDL)γ-aminobutyric acid(GABA)receptors in insects,thereby impairing inhibitory neurotransmission.Some insect species,such as the diamondback moth(Plutella xylostella),possess more than one Rdl gene.The involvement of multiple Rdls in fipronil toxicity and resistance remains largely unknown.In this study,we investigated the roles of two Rdl genes,PxRdl1 and PxRdl2,in P.xylostella fipronil action.In Xenopus oocytes,RvRDL2 receptors were 40 times less sensitive to fipronil than P.vRDL1.P.vRDL2 receptors were also less sensitive to GABA compared with PxRDL1.Knockout of the fipronil-sensitive PxRdll reduced the fipronil potency 10-fold,whereas knockout of the fipronil-resistant PxRdl2 enhanced the fipronil potency 4.4-fold.Furthermore,in two fipronil-resistant diamondback moth field populations,PxRdl2 expression was elevated 3.7-and 4.1-fold compared with a susceptible strain,whereas PxRdl1 expression was comparable among the resistant and susceptible strains.Collectively,our results indicate antagonistic effects of PxRDLl and PxRDL2 on fipronil action in vivo and suggest that enhanced expression of fipronil-resistant PxRdl1 is potentially a new mechanism of fipronil resistance in insects.