Suppressing decoherence of noisy environment through filtering operator

2020 ◽  
Vol 34 (07) ◽  
pp. 2050051
Author(s):  
Zhiming Huang
Keyword(s):  
Quantum System ◽  
Quantum Coherence ◽  
Critical Time ◽  
Zero Temperature ◽  
Noisy Environment ◽  
Oscillatory Frequency ◽  
Time Points ◽  
Single Qubit ◽  
Amplitude Increase ◽  
Markovian Regime

Inevitable interaction between quantum system and environment will induce decoherence which would destroy the quantum coherence (QC) of quantum system. In this paper, we examine the QC behaviors for a single qubit locally coupled to the zero-temperature multiple bosonic reservoirs. Comparing the Markovian and non-Markovian QC behaviors, it is demonstrated that QC decays as decoherent time goes by, and non-Markovian QC exhibits obvious oscillating behaviors. The oscillatory frequency and amplitude increase with growing coupling strength and number of reservoirs. In addition, in non-Markovian regime, QC vanishes at some discrete critical time points. Finally, we reveal an effective method to suppress decoherence with filtering operation.

Multi-party qutrit-state sharing under decoherence

2020 ◽  
Vol 34 (12) ◽  
pp. 2050124
Author(s):  
Zhiming Huang ◽  
Zhimin He
Keyword(s):  
Quantum System ◽  
Quantum State ◽  
Quantum Coherence ◽  
Quantum Communication ◽  
Communication Protocol ◽  
Entangled State ◽  
Quantum State Sharing ◽  
Noisy Environment ◽  
Realistic Situation ◽  
Quantum Communication Protocol

Quantum state sharing plays an important role in both transmitting and protecting a quantum secret information. However, in a realistic situation, quantum communication protocol is inevitably affected by the decoherence and noise induced by the interaction between quantum system and environment, which often destroys quantum resource, such as degrading entangled state that is often used as the key resource of quantum communication. In this paper, we intend to investigate the influence of amplitude damping (AD) decoherence on multi-party qutrit-state sharing (MQSS) scheme. We firstly construct the noisy model of MQSS, and then analyze the effect of decoherence on the MQSS. In addition, the relation of variations between MQSS performance and quantum coherence is illustrated. Furthermore, we propose a partial measurement to enhance the performance of the MQSS under noisy environment.

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.

scholarly journals SUDDEN CHANGE OF QUANTUM DISCORD UNDER SINGLE QUBIT NOISE

2013 ◽  
Vol 11 (05) ◽  
pp. 1350048 ◽  
Author(s):  
LI-XING JIA ◽  
BO LI ◽  
R.-H. YUE ◽  
HENG FAN
Keyword(s):  
Quantum System ◽  
Quantum Correlation ◽  
Quantum Discord ◽  
Sudden Change ◽  
Entangled State ◽  
Noisy Environment ◽  
Noisy Environments ◽  
Single Qubit ◽  
Sudden Transition

We show that the sudden change of quantum correlation can occur even when only one part of the composite entangled state is exposed to a noisy environment. Our results are illustrated through the action of different noisy environments individually on a single qubit of quantum system. Composite noise on the whole of the quantum system is thus not the necessarily condition for the occurrence of sudden transition for quantum correlation.

scholarly journals Reading a Qubit Quantum State with a Quantum Meter: Time Unfolding of Quantum Darwinism and Quantum Information Flux

2019 ◽  
Vol 26 (04) ◽  
pp. 1950023
Author(s):  
Salvatore Lorenzo ◽  
Mauro Paternostro ◽  
G. Massimo Palma
Keyword(s):  
Quantum Information ◽  
Harmonic Oscillator ◽  
Quantum System ◽  
Quantum State ◽  
Common Theme ◽  
Quantum Harmonic Oscillator ◽  
Collision Model ◽  
Single Qubit ◽  
Quantum Darwinism

Quantum non-Markovianity and quantum Darwinism are two phenomena linked by a common theme: the flux of quantum information between a quantum system and the quantum environment it interacts with. In this work, making use of a quantum collision model, a formalism initiated by Sudarshan and his school, we will analyse the efficiency with which the information about a single qubit gained by a quantum harmonic oscillator, acting as a meter, is transferred to a bosonic environment. We will show how, in some regimes, such quantum information flux is inefficient, leading to the simultaneous emergence of non-Markovian and non-darwinistic behaviours.

scholarly journals Irreversible work versus fidelity susceptibility for infinitesimal quenches

2017 ◽  
Vol 31 (06) ◽  
pp. 1750065 ◽  
Author(s):  
Simone Paganelli ◽  
Tony J. G. Apollaro
Keyword(s):  
Quantum System ◽  
Excited States ◽  
Ground State ◽  
Finite Size ◽  
Scaling Relations ◽  
Zero Temperature ◽  
Finite Size Scaling ◽  
Ising Chain ◽  
Extra Term ◽  
Explicit Relation

We compare the irreversible work produced in an infinitesimal sudden quench of a quantum system at zero temperature with its ground state fidelity susceptibility, giving an explicit relation between the two quantities. We find that the former is proportional to the latter but for an extra term appearing in the irreversible work which includes also contributions from the excited states. We calculate explicitly the two quantities in the case of the quantum Ising chain, showing that at criticality they exhibit different scaling behaviors. The irreversible work, rescaled by square of the quench’s amplitude, exhibits a divergence slower than that of the fidelity susceptibility. As a consequence, the two quantities obey also different finite-size scaling relations.

Non-Markovian Dynamics of Spin Squeezing Under Detuning Modulation

2017 ◽  
Vol 24 (01) ◽  
pp. 1750003
Author(s):  
Xing Xiao ◽  
Jia-Ju Wu ◽  
Wo-Jun Zhong ◽  
Yan-Ling Li
Keyword(s):  
Sudden Death ◽  
Open Systems ◽  
Spin Squeezing ◽  
Zero Temperature ◽  
Quantum Metrology ◽  
Markovian Dynamics ◽  
Long Time ◽  
Markovian Regime

The dynamics of spin squeezing of an ensemble of N separate spin-1/2 particles, each coupled to a zero-temperature non-Markovian reservoir have been investigated. We show that the initial spin squeezing could be prolonged for a long time by utilizing detuning modification. We further explore that the spin squeezing sudden death (SSSD) could be circumvented with the increasing of detuning. By comparison with the results in Markovian regime with detuning and those in non-Markovian regime without detuning, we conclude that the disappearance of SSSD and the robust preservation of spin squeezing should be attributed to the combination of detuning and non-Markovian effect. The present results may be of direct importance for quantum metrology in open systems.

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