Transition from isolated to overlapping resonances in the open system of interacting fermions

Celardo, G. L.; Izrailev, F. M.; Zelevinsky, V. G.; Berman, G. P.

doi:10.1016/j.physletb.2007.11.044

Cited by 26 publications

(43 citation statements)

References 33 publications

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“…This simple example suggests that a transition between these two regimes may take place at a critical value of γ. Roughly, the transition occurs when γ/D ≈ 1 [5,13,24,25], where D is the mean level spacing of H 0 . Note that the qualitative criterion γ/D ≈ 1 for the transition to superradiance is valid in the case of uniform density of states and negligible energy shift; when the density of states is not uniform, the transition to superradiance occurs as a hierarchical process [24].…”

Section: Effective Hamiltonianmentioning

confidence: 99%

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Superradiance transition in one-dimensional nanostructures: An effective non-Hermitian Hamiltonian formalism

2009

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Using an energy-independent non-Hermitian Hamiltonian approach to open systems, we fully describe transport through a sequence of potential barriers as external barriers are varied. Analyzing the complex eigenvalues of the non-Hermitian Hamiltonian model, a transition to a superradiant regime is shown to occur. Transport properties undergo a strong change at the superradiance transition, where the transmission is maximized and a drastic change in the structure of resonances is demonstrated. Finally, we analyze the effect of the superradiance transition in the Anderson localized regime.

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Section: Effective Hamiltonianmentioning

confidence: 99%

“…The effective non-Hermitian Hamiltonian approach to open systems has been used mainly under the assumptions of Random Matrix Theory (RMT) [12,13]. More realistic systems have also been studied, such as nuclei [14] and billiards [15].…”

Section: Introductionmentioning

confidence: 99%

Superradiance transition in one-dimensional nanostructures: An effective non-Hermitian Hamiltonian formalism

2009

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“…For those sites which are not connected to sinks, the corresponding ET rates vanish. Under reasonable assumptions, this type of model can be described by an effective non-Hermitian Hamiltonian [2,3,4,5,6].Then, this approach becomes similar to those used in describing the so-called "superradiance transition" (ST) in systems in which the discrete (intrinsic) energy states interact with the continuum spectra [7,8,9,10,11,12]. In these systems, the ST usually occurs when the resonances start to overlap.…”

mentioning

confidence: 99%

“…Then, this approach becomes similar to those used in describing the so-called "superradiance transition" (ST) in systems in which the discrete (intrinsic) energy states interact with the continuum spectra [7,8,9,10,11,12]. In these systems, the ST usually occurs when the resonances start to overlap.…”

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Superradiance Transition and Nonphotochemical Quenching in Photosynthetic Complexes

et al. 2015

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We demonstrate numerically that superradiance could play a significant role in nonphotochemical quenching (NPQ) in light-harvesting complexes. Our model consists of a network of five interconnected sites (discrete excitonic states) that are responsible for the NPQ mechanism. Damaging and charge transfer states are linked to their sinks (independent continuum electron spectra), in which the chemical reactions occur. The superradiance transition in the charge transfer (or in the damaging) channel, occurs at particular electron transfer rates from the discrete to the continuum electron spectra, and can be characterized by a segregation of the imaginary parts of the eigenvalues of the effective non-Hermitian Hamiltonian. All five excitonic sites interact with their protein environment that is modeled by a random stochastic process. We find the region of parameters in which the superradiance transition into the charge transfer channel takes place. We demonstrate that this superradiance transition has the capability of producing optimal NPQ performance. W hen sunlight intensity is too high, damaging processes (such as singlet oxygen production) occur, that can destroy the photosynthetic organisms. To survive intense sunlight fluctuations, photosynthetic organisms have evolved many protective strategies, including nonphotochemical quenching (NPQ) [1]. (See also references therein.) Using this strategy, light-harvesting complexes (LHCs) experience geometrical reorganizations due to the conformational changes of their protein environments. As a result, the damaging channels are partly suppressed, and the excessive sunlight energy is transfered to the non-damaging, quenching channel(s), that are opened in this regime.In modeling the NPQ mechanisms, it is possible to characterize the sites of the LHCs by the discrete excitonic energy states, |n , n being the number of site, associated with the light-sensitive chlorophyll or carotenoid molecule. Then, both the damaging and undamaging channels can be characterized by their corresponding sinks, |Sn , that provide independent continuum electron energy spectra [2]. These sinks can have very complex structures, and they can be responsible for primary charge separation processes, as in the photosynthetic reaction centers (RCs) [3,4], for creation of charge transfer states, for singlet oxygen production [2], and for many other quasi-reversible chemical reactions. Generally, a particular sink, |Sn , is connected to a particular site, |n . The energy transfer from this state to its sink is characterized by the electron transfer (ET) rate, Γn. For those sites which are not connected to sinks, the corresponding ET rates vanish. Under reasonable assumptions, this type of model can be described by an effective non-Hermitian Hamiltonian [2,3,4,5,6].Then, this approach becomes similar to those used in describing the so-called "superradiance transition" (ST) in systems in which the discrete (intrinsic) energy states interact with the continuum spectra [7,8,9,10,11,12]. In these systems, th...

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Interplay of superradiance and disorder in the Anderson Model

Celardo

Biella

Kaplan

et al. 2012

Fortschritte der Physik

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Using a non-Hermitian Hamiltonian approach to open systems, we study the interplay of disorder and superradiance in a one-dimensional Anderson model. Analyzing the complex eigenvalues of the non-Hermitian Hamiltonian, a transition to a superradiant regime is shown to occur. As an effect of openness the structure of eigenstates undergoes a strong change in the superradiant regime: we show that the sensitivity to disorder of the superradiant and the subradiant subspaces is very different; superradiant states remain delocalized as disorder increases, while subradiant states are sensitive to the degree of disorder.Comment: 7 pages, submitted to the special issue on "Physics with non-Hermitian operators: Theory and Experiment" of the journal "Fortschritte der Physik - Progress of Physics

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Transition from isolated to overlapping resonances in the open system of interacting fermions

Cited by 26 publications

References 33 publications

Superradiance transition in one-dimensional nanostructures: An effective non-Hermitian Hamiltonian formalism

Superradiance transition in one-dimensional nanostructures: An effective non-Hermitian Hamiltonian formalism

Superradiance Transition and Nonphotochemical Quenching in Photosynthetic Complexes

Interplay of superradiance and disorder in the Anderson Model

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