Control and manipulation of entanglement between two coupled qubits by fast pulses

Abstract

We have investigated the analytical and numerical dynamics of entanglement for two qubits that interact with each other via Heisenberg XXX-type interaction and subject to local time-specific external kick and Gaussian pulse-type magnetic fields in x-y plane. The qubits have been assumed to be initially prepared in different pure separable and maximally entangled states and the effect of the strength and the direction of external fast pulses on concurrence has been investigated. The carefully designed kick or pulse sequences are found to enable one to obtain constant long-lasting entanglement with desired magnitude. Moreover, the time ordering effects are found to be important in the creation and manipulation of entanglement by external fields.

The influence of spontaneously generated coherence on atom-photon entanglement in a Λ-type system with an incoherent pump

“…In particular, preparation [1,8], manipulation [9] and purification [10] of the quantum entanglement are always important concerns in the field of quantum information and quantum optics. As a kind of physical resources, the quantum entanglement can play a key role in all aspects of quantum information, such as quantum teleprotation [11], quantum superdense coding [12], quantum secret sharing [13], quantum algorithm [14], etc.…”