We investigate the teleportation of an entangled two-qubit state using three-qubit GHZ and W channels. The effects of white noise on the average teleportation fidelity and amount of entanglement transmitted are also studied.
The bipartite quantum teleportation with a three-qubit mixture of GHZ and W states as a quantum channel is discussed. When the quantum channel is a mixed state consisting of the GHZ state plus small perturbed W state, the entanglement of the channel becomes zero when the average fidelity FˉGHZ is less than 0.775. This means that the mixed state cannot play an any role as a quantum channel at FˉGHZ≤0.775. For the case of the mixed state consisting of the W state plus small perturbed GHZ state it turn out that this mixed state cannot play a role as a quantum channel at FˉW≤0.833.
Quantum teleportation plays a significant role in the field of quantum communication. This paper investigates quantum teleportation through a noisy environment by using GHZ state and non-standard W state as quantum channels. We analyze the efficiency of quantum teleportation by solving analytically a master equation in Lindblad form. Following the quantum teleportation protocol, we obtain the fidelity of quantum teleportation as a function of evolution time. The calculation results show that the teleportation fidelity using non-standard W is higher in comparison to GHZ state at the same evolution time. Moreover, we consider the efficiency of teleportation with weak measurements and reverse quantum measurement under amplitude damping noise. Our analysis suggests that the teleportation fidelity using non-standard W is also more robust to noise than GHZ state in the same conditions. Interestingly, we found that weak measurement and its reverse operation have no positive effect on the efficiency of quantum teleportation by using GHZ and non-standard W state in the amplitude damping noise environment. In addition, we also demonstrate the efficiency of quantum teleportation can be improved by making minor modifications to the protocol.
Abstract We investigate the criteria for two-qubit states that could be transmitted via W-state. The appropriate criterias are entangled states which have maximum number of terms equal to number of channel terms and maximum of two different constants. We have also shown quantum teleportation of a particular type of two-qubit state via three-qubit GHZ-like states, with Alice possesses the first qubit of the channel and the rest belongs to Bob. GHZ-like state is an entangled state which has different characteristic from GHZ state. It is stronger against particle loss than GHZ state. Furthermore, GHZ-like states which can teleport a particular type of two-qubit state are GHZ-like states which have two terms.
Abstract Quantum communication is an integral part of quantum computing, where teleportation of a quantum state has gained significant attention from researchers. Many teleportation schemes have been introduced in the recent past. In this study, the authors compare the teleportation of a single‐qubit message among different entangled channels such as the two‐qubit Bell channel, three‐qubit GHZ channel, two/three‐qubit cluster states, a highly entangled five‐qubit state (Brown et al.) and the six‐qubit state (Borras et al.). The authors calculate and compare the quantum costs for these channels. The authors also study the effects of six noise models: bit‐flip noise, phase‐flip noise, bit‐phase‐flip noise, amplitude damping, phase damping and depolarising error. These noise models may affect the communication channel used for teleportation. An investigation of the variation of the initial state's fidelity is performed for the teleported state in the presence of the noise model. It is observed that the fidelity decreases in all the entangled channels as the noise parameter η increases in the range [0, 0.5] for all the noise models. The fidelity shows an upward trend in the Bell, GHZ and three‐qubit cluster state channels, as η varies in the range [0.5, 1.0] for all the noise models. However, in the rest of the three channels, the fidelity substantially decreases in the case of amplitude damping, phase damping and depolarising noise, and even it reaches zero for η = 1 in Brown et al. and Borras et al. channels.
Abstract This study investigates the effect of noise on two-qubit quantum teleportation through a four-qubit entangled channel theoretically. Therefore, in this study a comparison of two states of teleportation through ideal and noisy channel was carried out. The noisy channel can have the effect of bit-flip channel and phase-flip channel. From these two effects, it is found that the channel transforms in-to a mixed state. If the noise is neglected, the channel is pure state. Then, this channel is measured and fidelity is calculated. The fidelity of an ideal environment is 1. This indicates that the teleportation was successfully sent and at the same time confirms the teleportation behavior under ideal conditions. In noisy environments, fidelity can be less than 1. Two factors in noisy environment that affect fidelity are noise factor (p) and the orginal parameter states (transmission coefficients). In this calculation, for the bit flip noise, we observed that as the values of the coefficient values of transmitted state increase, the fidelity value increases. Meanwhile, for the phase flip noise, we observed that as the values of the coefficient values of transmitted state increase, the fidelity value decreases.