Non-Markovian dynamics of single- and two-qubit systems interacting with Gaussian and non-Gaussian fluctuating transverse environments

Rossi, Matteo A. C.; Paris, Matteo G. A.

doi:10.1063/1.4939733

Cited by 36 publications

(29 citation statements)

References 64 publications

(73 reference statements)

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“…0 Î is the qubit energy in the absence of noise (energy degeneracy is assumed), ν is the strength of the Q-E coupling and t Q J ( ) denotes a discrete stochastic term giving rise to the external RTN. To this end, the stochastic parameter t Q J ( ) behaves as a bistable fluctuator i.e., it switches randomly between two values with a certain switching rate γ [67]. The autocorrelation function of the stochastic parameter is an exponential decaying function given by:…”

Section: The Physical Model and Hamiltonianmentioning

confidence: 99%

Dynamics of entanglement and state-space trajectories followed by a system of four-qubit in the presence of random telegraph noise: common environment (CE) versus independent environments (IEs)

Kenfack¹,

Tchoffo²,

Jipdi³

et al. 2018

J. Phys. Commun.

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The paper investigates the dynamics of entanglement and explores some geometrical characteristics of the trajectories in state space, in four-qubit Greenberger-Horne-Zeilinger (GHZ) -and W-type states, coupled to common and independent classical random telegraph noise (RTN) sources. It is shown from numerical simulations that: (i) the dynamics of entanglement depends drastically not only on the input configuration of the qubits and the presence or absence of memory effects, but also on whether the qubits are coupled to the RTN in a CE or IEs; (ii) a considerable amount of entanglement can be indefinitely trapped when the qubits are embedded in a CE; (iii) the CE configuration preserves better the entanglement initially shared between the qubits than the IEs configuration, however, for W-type states, there is a period of time and/or certain values of the purity for which, the opposite can be found. Thanks to the results obtained in our earlier works on three-qubit models, we are able to conclude that entanglement becomes more robustly protected from decay when the number of qubits of the system increases. Finally, we find that the trajectories in state space of the system quantified by the quantum Jensen Shannon divergence (QJSD) between the time-evolved states of the qubits and some reference states may be curvilinear or chaotic.

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Section: The Physical Model and Hamiltonianmentioning

confidence: 99%

Dynamics of entanglement and state-space trajectories followed by a system of four-qubit in the presence of random telegraph noise: common environment (CE) versus independent environments (IEs)

Kenfack¹,

Tchoffo²,

Jipdi³

et al. 2018

J. Phys. Commun.

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“…The noise is modeled as random telegraph noise (RTN) affecting the links of the graph with tunable strength, ranging from a weak perturbation of the hopping amplitudes to a strength comparable to the coupling, inducing dynamical percolation. Our choice for the noise is motivated by its relevance in systems of interest for quantum information processing [17][18][19][20][21], and by the fact that RTN is at the root of the 1/ f noise affecting superconducting qubits [22]. In recent years some works have addressed the properties of CTQWs on the one-dimensional lattice subject to random telegraph noise [23][24][25][26], also in the presence of spatial correlations [27].…”

Section: Introductionmentioning

confidence: 99%

Quantum spatial search on graphs subject to dynamical noise

et al. 2018

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We address quantum spatial search on graphs and its implementation by continuous-time quantum walks in the presence of dynamical noise. In particular, we focus on search on the complete graph and on the star graph of order N, also proving that noiseless spatial search shows optimal quantum speedup in the latter, in the computational limit N 1. The noise is modeled by independent sources of random telegraph noise (RTN), dynamically perturbing the links of the graph. We observe two different behaviors depending on the switching rate of RTN: fast noise only slightly degrades performance, whereas slow noise is more detrimental and, in general, lowers the success probability. In particular, we still find a quadratic speed-up for the average running time of the algorithm, while for the star graph with external target node we observe a transition to classical scaling. We also address how the effects of noise depend on the order of the graphs, and discuss the role of the graph topology. Overall, our results suggest that realizations of quantum spatial search are possible with current technology, and also indicate the star graph as the perfect candidate for the implementation by noisy quantum walks, owing to its simple topology and nearly optimal performance also for just few nodes.

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“…The effects of RTN on two-level systems are also studied in the field of quantum information [26][27][28], with particular attention to solid-state devices [29]. Uchiyama et al [17] have analyzed the effect of spatial and temporal correlations on EET in a multi-site model by using a Ornstein-Uhlenbeck noise process to describe the environment, and observe that negative spatial correlation of the noise is the most effective in helping the EET.…”

Section: Introductionmentioning

confidence: 99%

Efficient quantum transport in a multi-site system combining classical noise and quantum baths

2020

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We study the population dynamics and quantum transport efficiency of a multi-site dissipative system driven by a random telegraph noise (RTN) by using a variational polaron master equation for both linear chain and ring configurations. By using two different environment descriptions-RTN only and a thermal bath+RTN-we show that the presence of the classical noise has a non-trivial role on quantum transport. We observe that there exist large areas of parameter space where the combined bath+RTN influence is clearly beneficial for populating the target state of the transport, and for average trapping time and transport efficiency when accounting for the presence of the reaction center via the use of the sink. This result holds for both of the considered intra-site coupling configurations including a chain and ring. In general, our formalism and achieved results provide a platform for engineering and characterizing efficient quantum transport in multi-site systems both for realistic environments and engineered systems.

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Non-Markovian dynamics of single- and two-qubit systems interacting with Gaussian and non-Gaussian fluctuating transverse environments

Cited by 36 publications

References 64 publications

Dynamics of entanglement and state-space trajectories followed by a system of four-qubit in the presence of random telegraph noise: common environment (CE) versus independent environments (IEs)

Dynamics of entanglement and state-space trajectories followed by a system of four-qubit in the presence of random telegraph noise: common environment (CE) versus independent environments (IEs)

Quantum spatial search on graphs subject to dynamical noise

Efficient quantum transport in a multi-site system combining classical noise and quantum baths

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