Decoherence induced by interacting quantum spin baths

Rossini, Davide; Calarco, Tommaso; Giovannetti, Vittorio; Montangero, Simone; Fazio, Rosario

doi:10.1103/physreva.75.032333

Cited by 208 publications

(273 citation statements)

References 52 publications

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“…Subsequently, these studies have been generalized to twodimensional systems 13,14 and the role of topology 13 and the dynamical topological order parameter have been investigated 15 . We note in the passing that the rate function I(t) is related to the Loschmidt echo which has been studied in the context of decoherence [17][18][19][20][21][22][23][24][25][26] and the work-statistics 27,28 . The finite temperature counterpart of the Loschmidt echo 29 , namely the characteristic function has also been useful in studies of the entropy generation and emergent thermodynamics in quenched quantum systems 30,31 .…”

Section: Introductionmentioning

confidence: 99%

Tuning the presence of dynamical phase transitions in a generalizedXYspin chain

Divakaran¹,

Sharma²,

Dutta³

2016

Phys. Rev. E

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We study an integrable spin chain with three spin interactions and the staggered field (λ) while the latter is quenched either slowly (in a linear fashion in time (t) as t/τ where t goes from a large negative value to a large positive value and τ is the inverse rate of quenching) or suddenly. In the process, the system crosses quantum critical points and gapless phases. We address the question whether there exist non-analyticities (known as dynamical phase transitions (DPTs)) in the subsequent real time evolution of the state (reached following the quench) governed by the final time-independent Hamiltonian. In the case of sufficiently slow quenching (when τ exceeds a critical value τ1), we show that DPTs, of the form similar to those occurring for quenching across an isolated critical point, can occur even when the system is slowly driven across more than one critical point and gapless phases. More interestingly, in the anisotropic situation we show that DPTs can completely disappear for some values of the anisotropy term (γ) and τ , thereby establishing the existence of boundaries in the (γ − τ ) plane between the DPT and no-DPT regions in both isotropic and anisotropic cases. Our study therefore leads to a unique situation when DPTs may not occur even when an integrable model is slowly ramped across a QCP. On the other hand, considering sudden quenches from an initial value λi to a final value λ f , we show that the condition for the presence of DPTs is governed by relations involving λi, λ f and γ and the spin chain must be swept across λ = 0 for DPTs to occur.

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Section: Introductionmentioning

confidence: 99%

Tuning the presence of dynamical phase transitions in a generalizedXYspin chain

Divakaran¹,

Sharma²,

Dutta³

2016

Phys. Rev. E

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“…In particular, we will focus on the Gaussian decay [4,11,13,14,22,23] and explain the origin of the so-called universal regime of the Gaussian decay [4,13].…”

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confidence: 99%

Decoherence of a quantum system coupled to an XY spin chain: Role of the initial state of the spin chain

Yuan

Zhang

et al. 2016

Annals of Physics

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We study the decoherence of a coupled quantum system consisting of a central spin and its correlated environment described by a general XY spin-chain model. We make it clear that the evolution of the coherence factor sensitively depends on the initial states of the environment spinchain. Specially, the dynamical evolution of the coherence factor of the central spin is numerically and analytically investigated in both weak and strong coupling cases for different initial states including thermal equilibrium state. In both weak and strong coupling regimes, the decay of the coherence factor can be approximated by a Gaussian and in the strong coupling regime the coherence factor oscillate rapidly under a Gaussian envelope. The width of the Gaussian decay (envelope) has been studied in details and we explained the origin of the so-called universal regime.

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“…At the same time, it is known that decoherence is sensitive to quantum critical changes in the bath and that the correlation length of the environment can influence the rate of loss of quantumness in a system [16][17][18][19][20][21]. A possible justification for this behavior can be found in the monogamous nature of entanglement [22].…”

Section: Introductionmentioning

confidence: 99%

Decoherence-assisted energy transfer and quantum criticalities

Giorgi¹,

Busch²

2012

Phys. Rev. A

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Type of publicationArticle (peer-reviewed) We study the dynamics of a two-level quantum system interacting with an external environment that takes the form of an XY spin chain in the presence of an external magnetic field. While the presence of the bath itself can enhance the transition probability from the lower level to the upper level of the system, we show that this noise-assisted phenomenon is sensitive to a change of the quantum phase of the environment. The derivative of the transition probability displays a maximum in correspondence with the critical value of the applied field in the case of both isotropic and anisotropic chains.

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Decoherence induced by interacting quantum spin baths

Cited by 208 publications

References 52 publications

Tuning the presence of dynamical phase transitions in a generalizedXYspin chain

Tuning the presence of dynamical phase transitions in a generalizedXYspin chain

Decoherence of a quantum system coupled to an XY spin chain: Role of the initial state of the spin chain

Decoherence-assisted energy transfer and quantum criticalities

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