Realization of a universal and phase-covariant quantum cloning machine in separate cavities

Abstract

We present a scheme to realize a special quantum cloning machine in separate cavities. The quantum cloning machine can copy the quantum information from a photon pulse to two distant atoms. Choosing the different parameters, the method can perform optimal symmetric (asymmetric) universal quantum cloning and optimal symmetric (asymmetric) phase-covariant cloning.

Implementing a quantum cloning machine in separate cavities via the optical coherent pulse as a quantum communication bus

“…The distinct advantage of our scheme is that (1) the quantum information is encoded into discrete variables (DVs), namely, the electron-spin system in the individual cavity while the CVs mode, the optical coherent pulse, plays the role of a quantum communication bus to mediate interactions. In those schemes [28][29][30][31][32][33][34][35][36] with single-photon-based qubus, enormous difficulties arise due to the requirements on the generation and detection of the photons. As is known to all, the performance of a successful near-deterministic gate is indispensable from efficient detectors which unambiguously detect a single photon.…”

“…In the present scheme, the optical coherent pulse, called a quantum communication 'Corresponding author: yeliu@ahu.edu.cn bus (qubus), sequentially interacts with two electron-spin systems placed in the separate cavities. However, in those schemes [28][29][30][31][32][33][34][35][36] with single-photon-based qubus, enormous difficulties appear due to the demanding requirements on the generation and detection of the photons. The present approach can circumvent this obstacle by using the continuous variables (CVs) mode as qubus, namely, the optical coherent pulse.…”

“…Thus it plays only the role of a catalyst. The measurement-free operation for qubus avoids measurement-induced errors in contrast to the previous schemes [28][29][30] and the present cloning transformation becomes deterministic without measurement-result-dependent postselection [37][38][39] or any feedforward operations on the qubits. Due to the deterministic and measurement-free opera tion, the present scheme has high efficiency with high success probability.…”

Implementing of Quantum Cloning with Spatially Separated Quantum Dot Spins

“…Because quantum cloning has a wide applications in quantum information [24,25], it is very significant to realize quantum cloning. Recently, many schemes for realizing different quantum cloning have been proposed [26][27][28][29][30][31][32], and some experimental realizations have also reported by using different physical systems [33][34][35][36].…”

Quantum Multi-User Broadcast Protocol for the “Platform as a Service” Model

“…Yan [8] proposed a quantum secret sharing protocol between multiparty m members in Group 1 and multiparty n members in Group 2 using a sequence of single photons. Another extension of the theory of various Quantum Cloning Machines (QCM) protocols [9,10,11,12,13,14] has been designed and their applications and implementations have been studied, both theoretically and experimentally. The research of quantum cloning and deep application are continuously developing.…”