Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Entropy

Improving the Capacity of Quantum Dense Coding and the Fidelity of Quantum Teleportation by Weak Measurement and Measurement Reversal

Meijiao Wang, Bing Sun, Lianzhen Cao, Yang Yang, Xia Liu, Xinle Wang, Jia-Qiang Zhao

Published Apr 29, 2023• 11 citations
Publisher

Abstract

A protective scheme of quantum dense coding and quantum teleportation of the X-type initial state is proposed in amplitude damping noisy channel with memory using weak measurement and measurement reversal. Compared with the noisy channel without memory, the memory factor improves both the capacity of quantum dense coding and the fidelity of the quantum teleportation to a certain extent for the given damping coefficient. Although the memory factor can inhibit decoherence in some degree, it cannot eliminate it completely. In order to further overcome the influence of the damping coefficient, the weak measurement protective scheme is proposed, which found that the capacity and the fidelity can be efficiently improved by adjusting weak measurement parameter. Another practical conclusion is that, among the three initial states, the weak measurement protective scheme has the best protective effect on the Bell-state in terms of the capacity and the fidelity. For the channel with no memory and full memory, the channel capacity of quantum dense coding reaches two and the fidelity of quantum teleportation reaches one for the bit system; the Bell system can recover the initial state completely with a certain probability. It can be seen that the entanglement of the system can be well protected by the weak measurement scheme, which provides a good support for the realization of quantum communication.

DOI
10.3390/e25050736

Related papers

Protecting the entanglement of two-qubit over quantum channels with memory via weak measurement and quantum measurement reversal*

Meijiao Wang, Yun- Jie Xia, Yang Yang +4 more

Based on the quantum technique of the weak measurement and quantum measurement reversal (WMR), we propose a scheme to protect entanglement for an entangled two-qubit pure state from four typical quantum noise channels with memory, i.e., the amplitude damping channel, the phase damping channel, the bit flip channel, and the depolarizing channel. For a given initial state | ψ 〉 = a| 00 〉 + d| 11 〉, it is found that the WMR operation indeed helps to protect entanglement from the above four quantum channels with memory, and the protection effect of WMR scheme is better when the coefficient a is small. For the other initial state | ϕ 〉 = b| 01 〉 + c| 10 〉, the effect of the protection scheme is the same regardless of the coefficient b and the WMR operation can protect entanglement in the amplitude damping channel with memory. Moreover, the protection of entanglement in quantum noise channels without memory in contrast to the results of the channels with memory is more effective. For | ψ 〉 or | ϕ 〉, we also find that the memory parameters play a significant role in the suppression of entanglement sudden death and the initial entanglement can be drastically amplified. Another more important result is that the relationship between the concurrence, the memory parameter, the weak measurement strength, and quantum measurement reversal strength is found through calculation and discussion. It provides a strong basis for the system to maintain maximum entanglement in the nosie channel.

Chinese Physics B•Jul 15, 2020•7 citations

Weak-measurement assisted quantum teleportation fidelity enhancement under noise

Mohit Dhanik, Shraddha Sharma, Pitamber Mahanandia

This study presents an improved quantum teleportation protocol designed to enhance fidelity in noisy environments by combining weak measurements (WMs) with flip and reversal operations. In our scheme, Alice prepares a four-qubit entangled state and shares one of the entangled qubits with Bob, which serves as the quantum channel for teleporting an arbitrary single-qubit state. Since the communication channel is subject to noise, Alice performs a weak measurement on the shared qubit before transmission to reduce the impact of decoherence. Building upon existing WM-flipreversal frameworks, we propose a modified weak measurement and reversal (WMR) protocol tailored for different noises in a four-qubit entangled system. The approach applies WM and flip operations prior to transmission to enhance resilience against noise, followed by corresponding reversal operations after transmission to recover the original quantum state. We systematically compare the performance of our proposed WMR protocol with the previously proposed WM-flip-reversal method under three common noise models: amplitude damping channel (ADC), phase flip channel (PFC), and bit flip channel (BFC). Our analysis reveals that the modified WMR scheme achieves significantly higher teleportation fidelity and improved robustness, particularly in bit flip noise environments. These findings highlight the potential of optimized weak measurement strategies for developing more reliable and noise-tolerant quantum communication protocols

quant-pharXiv:2511.05155•Quantum Information Processing•Nov 10, 2025•0 citations

Enhancing quantum teleportation fidelity under decoherence via weak measurement with flips

Sajede Harraz, Shuang Cong, Juan Jose Nieto

Abstract Noiseless quantum channels are critical to share a pure maximally entangled state for performing an ideal teleportation protocol. However, in reality the shared entanglement severely degraded due to decoherence. In this paper, we propose a quantum teleportation channel protection scheme to enhance the teleportation fidelity in presence of decoherence. Before the entangled pair enters the decoherence channel, the weak measurement and flip operations are applied to transfer the qubit to a more robust state to the effects of the noise. After the decoherence channel the reversed flip operations and weak measurement reversal are applied to recover the initial state. We illustrate our protected teleportation scheme and compare it with a protocol based on weak measurement reversal. The numerical results show that the average teleportation fidelity of our proposed scheme can be significantly improved. Although the proposed entanglement protection scheme is probabilistic, after a successful entanglement transmission, we use the standard teleportation protocol which has probability one.

EPJ Quantum Technology•May 31, 2022•30 citations

Protected Quantum Teleportation Through Noisy Channel by Weak Measurement and Environment-Assisted Measurement

Sajede Harraz, Shuang Cong, Juan Jose Nieto

Quantum teleportation as a key protocol for quantum communication and quantum computing demonstrates the stark difference between quantum and classical information transmission. An ideal teleportation protocol requires pure maximally entangled state as the teleportation channel, while in real implementations the shared entanglement is severely degraded due to decoherence. In this letter, we propose a scheme to protect the quantum teleportation from decoherence by means of environment assisted measurement with weak measurements and flip operations. We show that the teleportation fidelity of our proposed scheme is significantly improved compared to teleportation with no protection and a teleportation protocol based on quantum measurement reversal. Also, the explicit formula of average teleportation fidelity and success probability of the entanglement protection are derived.

IEEE Communications Letters•Dec 27, 2021•29 citations

Perfect Quantum Teleportation in Memory Amplitude-Damping Channels Based on Preflipping and Environment-Assisted Measurement

Shiye Zhang, Sajede Harraz, Sen Kuang +1 more

Most existing quantum teleportation schemes do not consider the memory effect of noise, which is becoming increasingly serious in practical quantum communication. In this paper, we propose two quantum teleportation protocols for noisy memory channels: one based on pre-flipping (PF) and another incorporating pre-flipping with environment-assisted measurement (PF-EAM). In the PF protocol, a pre-flipping operation is applied to the entangled qubits before entanglement distribution to enhance robustness against noise. A recovery operator is then used to reverse the pre-flipping operation. In the PF-EAM protocol, environment-assisted measurement (EAM) is added to the entanglement distribution process, further improving teleportation fidelity. Since the pre-flipping operator in the two protocols is a fixed unitary operator, our protocols exclude additional parameters, which is unlike weak measurement (WM) schemes that rely on adjustable measurement strength. We derive the analytical expressions for the average fidelity and the success probability of our teleportation protocols. The results show that the pre-flipping operator in the PF protocol effectively enhances the average fidelity of quantum teleportation in a deterministic manner, while the fidelity of PF-EAM remains at constant 1, unaffected by the noise intensity in the channel. In addition, our PF-EAM achieves a higher success probability while maintaining the fidelity of 1 with respect to the existing unprotected teleportation protocol, protocol based on weak measurement and measurement reversal (WM-MR), and protocol based on quantum feed-forward control and environment-assisted measurement (QFFC-EAM) framework.

IEEE Transactions on Quantum Engineering•Jan 1, 2026•0 citations

Partial-measurement-enhanced high-dimensional superdense coding in amplitude damping channel with memory

Xing 兴 Xiao 肖, Zhipeng Yang, Yanling Li +2 more

Abstract We study the performance of high-dimensional superdense coding (HD-SDC) over an amplitude damping (AD) channel with memory and propose a protocol that leverages partial measurement and its reversal to enhance the channel capacity. By considering a two-qutrit system, we model the memory AD noise using a convex mixture of memoryless and perfectly memory AD channels. We demonstrate that the memory effect alone can mitigate the decay of the SDC capacity under noise. More significantly, we show that the application of partial measurement before the channel and its reversal after the channel can not only recover the capacity degraded by noise but, for certain non-maximally entangled initial states, even amplify it beyond the initial capacity. This amplification effect is governed by three key factors: the ground-state probability in the initial entangled state, the memory strength, and the partial measurement strength. Our results provide a practical strategy for enhancing quantum communication protocols in realistic noisy environments and highlight the synergistic benefits of memory noise and measurement-based control.

Chinese Physics B•Dec 4, 2025•0 citations
A protective scheme of quantum dense coding and quantum teleportation of the X-type initial state is proposed in amplitude damping noisy channel with memory using weak measurement and measurement reversal. Compared with the noisy channel without memory, the memory factor improves both the capacity of quantum dense coding and the fidelity of the quantum teleportation to a certain extent for the given damping coefficient. Although the memory factor can inhibit decoherence in some degree, it cannot eliminate it completely. In order to further overcome the influence of the damping coefficient, the weak measurement protective scheme is proposed, which found that the capacity and the fidelity can be efficiently improved by adjusting weak measurement parameter. Another practical conclusion is that, among the three initial states, the weak measurement protective scheme has the best protective effect on the Bell-state in terms of the capacity and the fidelity. For the channel with no memory and full memory, the channel capacity of quantum dense coding reaches two and the fidelity of quantum teleportation reaches one for the bit system; the Bell system can recover the initial state completely with a certain probability. It can be seen that the entanglement of the system can be well protected by the weak measurement scheme, which provides a good support for the realization of quantum communication.
Based on the quantum technique of the weak measurement and quantum measurement reversal (WMR), we propose a scheme to protect entanglement for an entangled two-qubit pure state from four typical quantum noise channels with memory, i.e., the amplitude damping channel, the phase damping channel, the bit flip channel, and the depolarizing channel. For a given initial state | ψ 〉 = a| 00 〉 + d| 11 〉, it is found that the WMR operation indeed helps to protect entanglement from the above four quantum channels with memory, and the protection effect of WMR scheme is better when the coefficient a is small. For the other initial state | ϕ 〉 = b| 01 〉 + c| 10 〉, the effect of the protection scheme is the same regardless of the coefficient b and the WMR operation can protect entanglement in the amplitude damping channel with memory. Moreover, the protection of entanglement in quantum noise channels without memory in contrast to the results of the channels with memory is more effective. For | ψ 〉 or | ϕ 〉, we also find that the memory parameters play a significant role in the suppression of entanglement sudden death and the initial entanglement can be drastically amplified. Another more important result is that the relationship between the concurrence, the memory parameter, the weak measurement strength, and quantum measurement reversal strength is found through calculation and discussion. It provides a strong basis for the system to maintain maximum entanglement in the nosie channel.
This study presents an improved quantum teleportation protocol designed to enhance fidelity in noisy environments by combining weak measurements (WMs) with flip and reversal operations. In our scheme, Alice prepares a four-qubit entangled state and shares one of the entangled qubits with Bob, which serves as the quantum channel for teleporting an arbitrary single-qubit state. Since the communication channel is subject to noise, Alice performs a weak measurement on the shared qubit before transmission to reduce the impact of decoherence. Building upon existing WM-flipreversal frameworks, we propose a modified weak measurement and reversal (WMR) protocol tailored for different noises in a four-qubit entangled system. The approach applies WM and flip operations prior to transmission to enhance resilience against noise, followed by corresponding reversal operations after transmission to recover the original quantum state. We systematically compare the performance of our proposed WMR protocol with the previously proposed WM-flip-reversal method under three common noise models: amplitude damping channel (ADC), phase flip channel (PFC), and bit flip channel (BFC). Our analysis reveals that the modified WMR scheme achieves significantly higher teleportation fidelity and improved robustness, particularly in bit flip noise environments. These findings highlight the potential of optimized weak measurement strategies for developing more reliable and noise-tolerant quantum communication protocols
Abstract Noiseless quantum channels are critical to share a pure maximally entangled state for performing an ideal teleportation protocol. However, in reality the shared entanglement severely degraded due to decoherence. In this paper, we propose a quantum teleportation channel protection scheme to enhance the teleportation fidelity in presence of decoherence. Before the entangled pair enters the decoherence channel, the weak measurement and flip operations are applied to transfer the qubit to a more robust state to the effects of the noise. After the decoherence channel the reversed flip operations and weak measurement reversal are applied to recover the initial state. We illustrate our protected teleportation scheme and compare it with a protocol based on weak measurement reversal. The numerical results show that the average teleportation fidelity of our proposed scheme can be significantly improved. Although the proposed entanglement protection scheme is probabilistic, after a successful entanglement transmission, we use the standard teleportation protocol which has probability one.
Quantum teleportation as a key protocol for quantum communication and quantum computing demonstrates the stark difference between quantum and classical information transmission. An ideal teleportation protocol requires pure maximally entangled state as the teleportation channel, while in real implementations the shared entanglement is severely degraded due to decoherence. In this letter, we propose a scheme to protect the quantum teleportation from decoherence by means of environment assisted measurement with weak measurements and flip operations. We show that the teleportation fidelity of our proposed scheme is significantly improved compared to teleportation with no protection and a teleportation protocol based on quantum measurement reversal. Also, the explicit formula of average teleportation fidelity and success probability of the entanglement protection are derived.
Most existing quantum teleportation schemes do not consider the memory effect of noise, which is becoming increasingly serious in practical quantum communication. In this paper, we propose two quantum teleportation protocols for noisy memory channels: one based on pre-flipping (PF) and another incorporating pre-flipping with environment-assisted measurement (PF-EAM). In the PF protocol, a pre-flipping operation is applied to the entangled qubits before entanglement distribution to enhance robustness against noise. A recovery operator is then used to reverse the pre-flipping operation. In the PF-EAM protocol, environment-assisted measurement (EAM) is added to the entanglement distribution process, further improving teleportation fidelity. Since the pre-flipping operator in the two protocols is a fixed unitary operator, our protocols exclude additional parameters, which is unlike weak measurement (WM) schemes that rely on adjustable measurement strength. We derive the analytical expressions for the average fidelity and the success probability of our teleportation protocols. The results show that the pre-flipping operator in the PF protocol effectively enhances the average fidelity of quantum teleportation in a deterministic manner, while the fidelity of PF-EAM remains at constant 1, unaffected by the noise intensity in the channel. In addition, our PF-EAM achieves a higher success probability while maintaining the fidelity of 1 with respect to the existing unprotected teleportation protocol, protocol based on weak measurement and measurement reversal (WM-MR), and protocol based on quantum feed-forward control and environment-assisted measurement (QFFC-EAM) framework.
Abstract We study the performance of high-dimensional superdense coding (HD-SDC) over an amplitude damping (AD) channel with memory and propose a protocol that leverages partial measurement and its reversal to enhance the channel capacity. By considering a two-qutrit system, we model the memory AD noise using a convex mixture of memoryless and perfectly memory AD channels. We demonstrate that the memory effect alone can mitigate the decay of the SDC capacity under noise. More significantly, we show that the application of partial measurement before the channel and its reversal after the channel can not only recover the capacity degraded by noise but, for certain non-maximally entangled initial states, even amplify it beyond the initial capacity. This amplification effect is governed by three key factors: the ground-state probability in the initial entangled state, the memory strength, and the partial measurement strength. Our results provide a practical strategy for enhancing quantum communication protocols in realistic noisy environments and highlight the synergistic benefits of memory noise and measurement-based control.