Speedup of quantum evolution of multiqubit entanglement states

Speedup of quantum evolution of multiqubit entanglement states

As is well known, quantum speed limit time (QSLT) can be used to characterize the maximal speed of evolution of quantum systems. We mainly investigate the QSLT of generalized N-qubit GHZ-type states and W-type states in the amplitude-damping channels. It is shown that, in the case N qubits coupled with independent noise channels, the QSLT of the entangled GHZ-type state is closely related to th...

Non-classicality and entanglement of symmetric multiqubit states

Quantum vs classical conceptions of nature continue to draw attention from the early days of quantum theory. Understanding decisive quantum features for which no classical explanation exist and their interrelations is of foundational significance. Further, identifying non-classical features is important in information processing tasks as it offers insights as to why quantum protocols outperform...

General monogamy relations of quantum entanglement for multiqubit W-class states

Is Entanglement Sufficient to Enable Quantum Speedup?

Spin squeezing and pairwise entanglement for symmetric multiqubit states

We show that spin squeezing implies pairwise entanglement for arbitrary symmetric multiqubit states. If the squeezing parameter is less than or equal to 1, we demonstrate a quantitative relation between the squeezing parameter and the concurrence for the even and odd states. We prove that the even states generated from the initial state with all qubits being spin down, via the one-axis twisting...