scholarly journals DYNAMICS OF INFORMATION IN THE PRESENCE OF DEFORMATION

2011 ◽  
Vol 09 (03) ◽  
pp. 937-946 ◽  
Author(s):  
NASSER METWALLY

The entanglement of atomic system consisting of two atoms interacting with a deformed cavity mode is quantified by the means of Bloch vectors and the cross dyadic of the traveling state inside the cavity. For large value of the deformation, the amplitude of Bloch vectors decrease very fast and consequently, the traveling state turns into mixed state quickly. The generated entangled state is used as quantum channel to implement quantum teleportation protocol. It is shown that both the deformed parameter and the number of photons inside the cavity play a central role in controlling the fidelity of the transmitted information.

2021 ◽  
pp. 2150249
Author(s):  
Vikram Verma

In this paper, by utilizing a nine-qubit entangled state as a quantum channel, we propose new schemes for symmetric and asymmetric cyclic controlled quantum teleportation (CYCQT). In our proposed schemes, four participants Alice, Bob, Charlie and David teleport their unknown quantum states cyclically among themselves with the help of a controller Eve. No participants can reconstruct the original states sent from the respective senders without the permission of the controller. Also, by considering same nine-qubit entangled state as a quantum channel, we propose a generalized scheme for CYCQT of multi-qubit states. In contrast to the previous CYCQT schemes involving three communicators and a controller, there are four communicators and a controller in the proposed schemes. Also, compared with previous CYCQT schemes, our proposed CYCQT schemes require less consumption of quantum resource and the intrinsic efficiency of the generalized scheme increases with the increase of number of qubits in the information states.


Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 352 ◽  
Author(s):  
Zhan-Yun Wang ◽  
Yi-Tao Gou ◽  
Jin-Xing Hou ◽  
Li-Ke Cao ◽  
Xiao-Hui Wang

We explicitly present a generalized quantum teleportation of a two-qubit entangled state protocol, which uses two pairs of partially entangled particles as quantum channel. We verify that the optimal probability of successful teleportation is determined by the smallest superposition coefficient of these partially entangled particles. However, the two-qubit entangled state to be teleported will be destroyed if teleportation fails. To solve this problem, we show a more sophisticated probabilistic resumable quantum teleportation scheme of a two-qubit entangled state, where the state to be teleported can be recovered by the sender when teleportation fails. Thus the information of the unknown state is retained during the process. Accordingly, we can repeat the teleportion process as many times as one has available quantum channels. Therefore, the quantum channels with weak entanglement can also be used to teleport unknown two-qubit entangled states successfully with a high number of repetitions, and for channels with strong entanglement only a small number of repetitions are required to guarantee successful teleportation.


2020 ◽  
Vol 34 (28) ◽  
pp. 2050261
Author(s):  
Vikram Verma

We propose a novel scheme for faithful bidirectional quantum teleportation (BQT) in which Alice can transmit an unknown N-qubit entangled state to Bob and at the same time Bob can transmit an unknown M-qubit entangled state to Alice by using a four-qubit entangled G-state as a quantum channel. We also propose a new scheme for cyclic QT of multi-qubit entangled states by using two G-states as a quantum channel. The advantage of our schemes is that it seems to be much simpler and requires reduced number of qubits in quantum channel as compared with the other proposed schemes.


2020 ◽  
pp. 2150145
Author(s):  
Vikram Verma

In 2017, Chen et al. [Quantum Inf. Process. 16 (2017) 201] proposed a scheme for cyclic quantum teleportation (CYQT) of three single-qubit information states among three participants by using six-qubit entangled state as a quantum channel. Following the work of Chen et al., we propose a new scheme for CYQT in which four participants cyclically teleport four arbitrary single-qubit information states among themselves by using two [Formula: see text]-states as a quantum channel. In our scheme, reverse CYQT can also be realized throughout changing the qubit pairs to be measured by each participant. We also generalize our scheme for CYQT of [Formula: see text]-qubit entangled states.


Author(s):  
Jinwei Wang ◽  
Liping Huang

In this paper, an asymmetric bidirectional controlled quantum teleportation via a six-qubit partially entangled state is given, in which Alice wants to transmit a two-qubit entangled state to Bob and Bob wants to transmit a single-qubit state to Alice on the same time. Although the six-qubit state as quantum channel is partially entangled, the teleportation is implemented deterministically. Furthermore, only Bell-state measurements, single-qubit measurements and some unitary operations are needed in the scheme.


2008 ◽  
Vol 22 (13) ◽  
pp. 2129-2137
Author(s):  
JIN-MING LIU ◽  
YI-CAI WANG ◽  
XIAO-QI XIAO

We present two schemes for probabilistically teleporting a two-atom entangled state using a three-atom partially entangled state as the quantum channel in cavity QED with the help of separate atomic measurements. The first scheme is only based on the interaction between two driven atoms and a quantized cavity mode in the large detuning limit, so the effects of both cavity decay and the thermal field are eliminated. In the second scheme, it is necessary to introduce an additional resonant cavity besides the thermal cavity to realize the teleportation, and the corresponding success probability is improved.


2011 ◽  
Vol 09 (supp01) ◽  
pp. 389-403 ◽  
Author(s):  
ANIRBAN PATHAK ◽  
ANINDITA BANERJEE

An efficient and economical scheme is proposed for the perfect quantum teleportation of n-qubit non-maximally entangled state of generalized Bell-type. A Bell state is used as the quantum channel in the proposed scheme. It is also shown that the controlled teleportation of this n-qubit state can be achieved by using a GHZ state or a GHZ-like state as quantum channel. The proposed schemes are economical because for the perfect and controlled teleportation of n-qubit non-maximally entangled state of generalized Bell-type, we only need a Bell state and a tripartite entangled state respectively. It is also established that there exists a family of 12 orthogonal tripartite GHZ-like states which can be used as quantum channel for controlled teleportation. The proposed protocols are critically compared with the existing protocols.


2007 ◽  
Vol 7 (8) ◽  
pp. 775-781
Author(s):  
S.-B. Zheng

We show that entanglement of multiple atoms can arise via resonant interaction with a displaced thermal field with a macroscopic photon-number. The cavity field acts as the catalyst, which is disentangled with the atomic system after the operation. Remarkably, the entanglement speed does not decrease as the average photon-number of the mixed thermal state increases. The atoms may evolve to a highly entangled state even when the photon-number of the cavity mode approaches infinity.


2010 ◽  
Vol 24 (10) ◽  
pp. 1271-1277 ◽  
Author(s):  
LI-YUN HU ◽  
HONG-YI FAN

By virtue of the entangled state representation, we show that the quantum teleportated state in Bob, after Alice makes an Einstein–Podolsky–Rosen measurement and Bob makes an appropriate unitary transformation on hearing Alice's measurement result via a classical channel, is described by [Formula: see text] where F(η)≡23〈η|ρ23|η〉23, ρ23 stands for a quantum channel in 2–3 modes, |η〉23 is the bipartite entangled state, and [Formula: see text] is a displacement transform performed by Bob.


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