Non-Markovinity of single qubit channels: analytical and numerical methods

2014 ◽  
Vol 92 (3) ◽  
pp. 230-235
Author(s):  
Jian-Song Zhang ◽  
Ai-Xi Chen
Keyword(s):  
Numerical Methods ◽  
Quantum States ◽  
Amplitude Damping ◽  
Single Qubit ◽  
Phase Damping ◽  
Bit Flip ◽  
Explicit Expressions

We propose methods to calculate non-Markovianity of four typical single qubit channels including flip (bit-flip, phase-flip, and bit-phase flip channels), depolarizing, phase damping, and amplitude damping channels analytically. Explicit expressions of non-Markovianity for some single qubit channels are obtained. For general channels we propose the Euler parametrization representation of quantum states to calculate non-Markovianity numerically.

ENTANGLEMENT-ASSISTED CLASSICAL CAPACITIES OF SOME SINGLE QUBIT QUANTUM NOISY CHANNELS

2002 ◽  
Vol 16 (12) ◽  
pp. 441-448 ◽  
Author(s):  
XIAN-TING LIANG ◽  
HONG-YI FAN
Keyword(s):  
Noisy Channels ◽  
Single Qubit ◽  
Phase Damping ◽  
Analytical Results ◽  
Bit Flip ◽  
Depolarizing Channel ◽  
Quantum Noisy Channels

In this paper, we calculate the entanglement-assisted classical capacities of the depolarizing channel, the phase damping channel, the phase flip channel, the bit flip channel, the bit-phase flip channel, the two-Pauli channel and the amplitude channel, and discuss the analytical results obtained. The Stokes papametrization representation of a qubit and the characteristic of unitary covariance of some quantum noisy channels are used in the calculations.

scholarly journals MINIMAL ENTANGLEMENT FIDELITIES OF SOME SINGLE QUBIT QUANTUM NOISY CHANNELS

2002 ◽  
Vol 16 (01n02) ◽  
pp. 19-25 ◽  
Author(s):  
XIAN-TING LIANG
Keyword(s):  
The Other ◽  
Noisy Channels ◽  
Amplitude Damping ◽  
Single Qubit ◽  
Phase Damping ◽  
Amplitude Damping Channel ◽  
Depolarizing Channel ◽  
Quantum Noisy Channels

The minimal entanglement fidelities of the phase damping channel, depolarizing channel, two-Pauli channel and amplitude damping channel are calculated. It is shown that for the same condition, the minimal fidelity of the phase damping channel is the biggest among the four channels. The minimal fidelity of the depolarizing channel is bigger than the other two.

Weak measurement for improving the efficiency of remote state preparation in noisy

2018 ◽  
Vol 18 (11&12) ◽  
pp. 975-987
Author(s):  
Ming-Ming Wang ◽  
Zhi-Guo Qu
Keyword(s):  
Communication Systems ◽  
Quantum Communication ◽  
Quantum Noise ◽  
Weak Measurement ◽  
Remote State Preparation ◽  
Amplitude Damping ◽  
Output State ◽  
State Preparation ◽  
Phase Damping ◽  
Bit Flip

Quantum communication provides a new way for transmitting highly sensitive information. But the existence of quantum noise inevitably affects the security and reliability of a quantum communication system. The technique of weak measurement and its reversal measurement (WMRM) has been proposed to suppress the effect of quantum noise, especially, the amplitude-damping noise. Taking a GHZ based remote state preparation (RSP) scheme as an example, we discuss the effect of WMRM for suppressing four types of quantum noise that usually encountered in real-world, i.e., not only the amplitude-damping noise, but also the bit-flip, phase-flip (phase-damping) and depolarizing noise. And we give a quantitative study on how much a quantum output state can be improved by WMRM in noisy environment. It is shown that the technique of WMRM has certain effect for improving the fidelity of the output state in the amplitude-damping noise, and only has little effect for suppressing the depolarizing noise, while has no effect for suppressing the bit-flip and phase-flip (phase-damping) noise. Our result is helpful for improving the efficiency of entanglement-based quantum communication systems in real implementation.

scholarly journals Decoherence assisted spin squeezing generation in superposition of tripartite GHZ and W states

2019 ◽  
Vol 198 ◽  
pp. 00015
Author(s):  
Kapil K. Sharma ◽  
Swaroop Ganguly
Keyword(s):  
Spin Squeezing ◽  
Spin Vector ◽  
Amplitude Damping ◽  
W States ◽  
Phase Damping ◽  
The Mean

In the present paper, we study spin squeezing under decoherence in the superposition of tripartite maximally entangled GHZ and W states. Here we use amplitude damping, phase damping and depolarisation channel. We have investigated the dynamics of spin squeezing with the interplay of super-position and decoherence parameters with different directions of the mean spin vector. We have found the mixture of GHZ and W states is robust against spin squeezing generation for amplitude damping and phase damping channels for certain directions of the mean spin vector. However, the depolarisation channel performs well for spin squeezing generation and generates permanent spin squeezing in the superposition of GHZ and W states.

scholarly journals One-step transfer or exchange of arbitrary multipartite quantum states with a single-qubit coupler

2015 ◽  
Vol 92 (5) ◽  
Author(s):  
Chui-Ping Yang ◽  
Qi-Ping Su ◽  
Shi-Biao Zheng ◽  
Siyuan Han
Keyword(s):  
Quantum States ◽  
Single Qubit ◽  
One Step

scholarly journals Analysis of Decoherence in Linear and Cyclic Quantum Walks

Optics ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 236-250
Author(s):  
Mahesh N. Jayakody ◽  
Asiri Nanayakkara ◽  
Eliahu Cohen
Keyword(s):  
Probability Distributions ◽  
Quantum Walks ◽  
Noisy Environments ◽  
Data Encoding ◽  
Phase Damping ◽  
Initial States ◽  
Binomial Transform ◽  
Bit Flip ◽  
Depolarizing Channel ◽  
Cyclic Path

We theoretically analyze the case of noisy Quantum walks (QWs) by introducing four qubit decoherence models into the coin degree of freedom of linear and cyclic QWs. These models include flipping channels (bit flip, phase flip and bit-phase flip), depolarizing channel, phase damping channel and generalized amplitude damping channel. Explicit expressions for the probability distribution of QWs on a line and on a cyclic path are derived under localized and delocalized initial states. We show that QWs which begin from a delocalized state generate mixture probability distributions, which could give rise to useful algorithmic applications related to data encoding schemes. Specifically, we show how the combination of delocalzed initial states and decoherence can be used for computing the binomial transform of a given set of numbers. However, the sensitivity of QWs to noisy environments may negatively affect various other applications based on QWs.

The one-way information deficit for a class of two-qubit states

2015 ◽  
Vol 13 (02) ◽  
pp. 1550012
Author(s):  
H. Eftekhari ◽  
E. Faizi
Keyword(s):  
Dynamic Behavior ◽  
Quantum States ◽  
Parameter Family ◽  
General Quantum ◽  
The One ◽  
Qubit States ◽  
Additional Assumptions ◽  
Explicit Expressions

So far, one-way information deficit (OWID) has been calculated explicitly only for Bell-diagonal states and the four-parameter family of X-states with additional assumptions and expressions for more general quantum states are not known. In this paper, we derive explicit expressions for OWID for a larger class of two-qubit states, namely, a five-parameter family of two-qubit states. The dynamic behavior of the OWID under decoherence channel is investigated and it is shown that the OWID is more robust against the decoherence than the entanglement.

Cyclic-controlled quantum operation teleportation in noisy environment

2019 ◽  
Vol 17 (07) ◽  
pp. 1950052
Author(s):  
Ren-Ju Liu ◽  
Ming-Qiang Bai ◽  
Fan Wu ◽  
Yu-Chun Zhang
Keyword(s):  
Quantum System ◽  
Unitary Operation ◽  
Quantum Operation ◽  
Noisy Environment ◽  
Noisy Environments ◽  
Final State ◽  
Single Qubit ◽  
Decoherence Rate ◽  
Qubit Operations ◽  
Bit Flip

A scheme is proposed for cyclic-controlled quantum operation teleportation (CCQOT) for three sides with EPR and cluster states. Under the control of David, Alice can implement an unknown single-qubit unitary operation on the remote Bob’s quantum system, while Bob can execute a single-qubit unitary operation on Charlie’s quantum system and Charlie can also perform an unknown single-qubit unitary operation on Alice’s quantum system. Our scheme can be generalized to [Formula: see text]) agents involved in the cycle to realize the transmission of single-qubit operations. Moreover, by replacing the quantum channels, we can change the cyclic direction of controlled qunatum operation teleportation (CQOT) from clockwise to counterclockwise. In addition, we discuss our scheme in four types of noisy environments (amplitude-damping, phase-damping, bit-flip and phase-flip noisy environment), and use fidelity to analyze the amount of information lost in the process of CCQOT due to noise. The results show that the fidelity is determined by decoherence rate and amplitude parameters of the final state.

QUANTUM STATE SHARING VIA THE GHZ STATE IN CAVITY QED WITHOUT JOINT MEASUREMENT

2006 ◽  
Vol 04 (05) ◽  
pp. 749-759 ◽  
Author(s):  
ZHENG-YAUN XUE ◽  
PING DONG ◽  
YOU-MIN YI ◽  
ZHUO-LIANG CAO
Keyword(s):  
Quantum State ◽  
Cavity Qed ◽  
Ghz State ◽  
Quantum States ◽  
Quantum State Sharing ◽  
Joint Measurement ◽  
Ghz States ◽  
Single Qubit ◽  
Arbitrary Quantum

We investigate schemes to securely distribute and reconstruct single-qubit and two-qubit arbitrary quantum states between two parties via tripartite GHZ states in cavity QED without joint measurement. Our schemes offer a simple way of demonstrating quantum state sharing in cavity QED. We also consider the generalization of our schemes to distribute and reconstruct a quantum state among many parties.

scholarly journals Environment-assisted error correction of single-qubit phase damping

2011 ◽  
Vol 84 (6) ◽  
Author(s):  
Benjamin Trendelkamp-Schroer ◽  
Julius Helm ◽  
Walter T. Strunz
Keyword(s):  
Error Correction ◽  
Single Qubit ◽  
Phase Damping
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