The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Eran Rabani - One of the best experts on this subject based on the ideXlab platform.
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sub ohmic to super ohmic crossover behavior in nonequilibrium quantum systems with Electron Phonon Interactions
Physical Review B, 2015Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:at zero temperature and zero bias, while for super-Ohmic ( s> 1) spectral densities this transition disappears. In this paper, we consider the influence of the Phonon-bath spectral density on the nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by the extended Holstein model. Using the reduced density matrix formalism combined with the multilayer multiconfiguration time-dependent Hartree approach, we investigate the dynamic response, the time scales for relaxation, as well as the existence of multiple long-lived solutions as the system-bath coupling changes from the sub- to the super-Ohmic cases. Bistability is shown to diminish for increasing powers of s similar to the spin-boson case. However, the physical mechanism and the dependence on the model parameters such as the typical bath frequency ωc and the polaron shift λ are rather distinct.
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sub ohmic to super ohmic crossover behavior in nonequilibrium quantum systems with Electron Phonon Interactions
Physical Review B, 2015Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The transition from weakly damped coherent motion to localization in the context of the spin-boson model has been the subject of numerous studies with distinct behavior depending on the form of the Phonon-bath spectral density $J\left(\ensuremath{\omega}\right)\ensuremath{\propto}{\ensuremath{\omega}}^{s}$. Sub-Ohmic ($sl1$) and Ohmic ($s=1$) spectral densities show a clear localization transition at zero temperature and zero bias, while for super-Ohmic ($sg1$) spectral densities this transition disappears. In this paper, we consider the influence of the Phonon-bath spectral density on the nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by the extended Holstein model. Using the reduced density matrix formalism combined with the multilayer multiconfiguration time-dependent Hartree approach, we investigate the dynamic response, the time scales for relaxation, as well as the existence of multiple long-lived solutions as the system-bath coupling changes from the sub- to the super-Ohmic cases. Bistability is shown to diminish for increasing powers of $s$ similar to the spin-boson case. However, the physical mechanism and the dependence on the model parameters such as the typical bath frequency ${\ensuremath{\omega}}_{c}$ and the polaron shift $\ensuremath{\lambda}$ are rather distinct.
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nonequilibrium quantum systems with Electron Phonon Interactions transient dynamics and approach to steady state
Physical Review B, 2014Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by a generalized Holstein model is presented. A combination of methodologies, including the reduced density matrix formalism, the multilayer multiconfiguration time-dependent Hartree method, and a time-dependent nonequilibrium Green’s function approach, is used to explore the transient behavior on multiple time scales as the system approaches steadystate.Thedotpopulationdynamicsonshorttointermediatetimesisgovernedbythedot-leadhybridization parameter (� ) and by the typical Phonon frequency (ωc) and depends on the location of the energy level of the dot relative to the bias window. At longer times, the dynamics shows a distinct behavior depending on whether the system is in the adiabatic or nonadiabatic regime, with a quantum dot occupation that may depend on the initial preparation of the Phonon degrees of freedom. A “phase” diagram of this effect as a function of the polaron shift (λ) for various Phonon frequencies is derived, suggesting the existence of bistability on experimentally observable time scales.
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nonequilibrium quantum systems with Electron Phonon Interactions transient dynamics and approach to steady state
Physical Review B, 2014Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by a generalized Holstein model is presented. A combination of methodologies, including the reduced density matrix formalism, the multilayer multiconfiguration time-dependent Hartree method, and a time-dependent nonequilibrium Green's function approach, is used to explore the transient behavior on multiple time scales as the system approaches steady state. The dot population dynamics on short to intermediate times is governed by the dot-lead hybridization parameter ($\ensuremath{\Gamma}$) and by the typical Phonon frequency (${\ensuremath{\omega}}_{c}$) and depends on the location of the energy level of the dot relative to the bias window. At longer times, the dynamics shows a distinct behavior depending on whether the system is in the adiabatic or nonadiabatic regime, with a quantum dot occupation that may depend on the initial preparation of the Phonon degrees of freedom. A ``phase'' diagram of this effect as a function of the polaron shift ($\ensuremath{\lambda}$) for various Phonon frequencies is derived, suggesting the existence of bistability on experimentally observable time scales.
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bistability in a nonequilibrium quantum system with Electron Phonon Interactions
Physical Review B, 2013Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Guy Cohen, Eran RabaniAbstract:The existence of more than one steady state in a many-body quantum system driven out of equilibrium has been a matter of debate, both in the context of simple impurity models and in the case of inelastic tunneling channels. In this paper, we combine a reduced density matrix formalism with the multilayer multiconfiguration time-dependent Hartree method to address this problem. This allows us to obtain a converged numerical solution of the nonequilibrium dynamics. Considering a generic model for quantum transport through a quantum dot with Electron-Phonon interaction, we prove that a unique steady state exists regardless of the initial Electronic preparation of the quantum dot, consistent with the converged numerical results. However, a bistability can be observed for different initial Phonon preparations. The effects of the Phonon frequency and strength of the Electron-Phonon couplings on the nonequilibrium dynamics and on the emergence of bistability is discussed.
Eli Y Wilner - One of the best experts on this subject based on the ideXlab platform.
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sub ohmic to super ohmic crossover behavior in nonequilibrium quantum systems with Electron Phonon Interactions
Physical Review B, 2015Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:at zero temperature and zero bias, while for super-Ohmic ( s> 1) spectral densities this transition disappears. In this paper, we consider the influence of the Phonon-bath spectral density on the nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by the extended Holstein model. Using the reduced density matrix formalism combined with the multilayer multiconfiguration time-dependent Hartree approach, we investigate the dynamic response, the time scales for relaxation, as well as the existence of multiple long-lived solutions as the system-bath coupling changes from the sub- to the super-Ohmic cases. Bistability is shown to diminish for increasing powers of s similar to the spin-boson case. However, the physical mechanism and the dependence on the model parameters such as the typical bath frequency ωc and the polaron shift λ are rather distinct.
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sub ohmic to super ohmic crossover behavior in nonequilibrium quantum systems with Electron Phonon Interactions
Physical Review B, 2015Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The transition from weakly damped coherent motion to localization in the context of the spin-boson model has been the subject of numerous studies with distinct behavior depending on the form of the Phonon-bath spectral density $J\left(\ensuremath{\omega}\right)\ensuremath{\propto}{\ensuremath{\omega}}^{s}$. Sub-Ohmic ($sl1$) and Ohmic ($s=1$) spectral densities show a clear localization transition at zero temperature and zero bias, while for super-Ohmic ($sg1$) spectral densities this transition disappears. In this paper, we consider the influence of the Phonon-bath spectral density on the nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by the extended Holstein model. Using the reduced density matrix formalism combined with the multilayer multiconfiguration time-dependent Hartree approach, we investigate the dynamic response, the time scales for relaxation, as well as the existence of multiple long-lived solutions as the system-bath coupling changes from the sub- to the super-Ohmic cases. Bistability is shown to diminish for increasing powers of $s$ similar to the spin-boson case. However, the physical mechanism and the dependence on the model parameters such as the typical bath frequency ${\ensuremath{\omega}}_{c}$ and the polaron shift $\ensuremath{\lambda}$ are rather distinct.
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nonequilibrium quantum systems with Electron Phonon Interactions transient dynamics and approach to steady state
Physical Review B, 2014Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by a generalized Holstein model is presented. A combination of methodologies, including the reduced density matrix formalism, the multilayer multiconfiguration time-dependent Hartree method, and a time-dependent nonequilibrium Green’s function approach, is used to explore the transient behavior on multiple time scales as the system approaches steadystate.Thedotpopulationdynamicsonshorttointermediatetimesisgovernedbythedot-leadhybridization parameter (� ) and by the typical Phonon frequency (ωc) and depends on the location of the energy level of the dot relative to the bias window. At longer times, the dynamics shows a distinct behavior depending on whether the system is in the adiabatic or nonadiabatic regime, with a quantum dot occupation that may depend on the initial preparation of the Phonon degrees of freedom. A “phase” diagram of this effect as a function of the polaron shift (λ) for various Phonon frequencies is derived, suggesting the existence of bistability on experimentally observable time scales.
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nonequilibrium quantum systems with Electron Phonon Interactions transient dynamics and approach to steady state
Physical Review B, 2014Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by a generalized Holstein model is presented. A combination of methodologies, including the reduced density matrix formalism, the multilayer multiconfiguration time-dependent Hartree method, and a time-dependent nonequilibrium Green's function approach, is used to explore the transient behavior on multiple time scales as the system approaches steady state. The dot population dynamics on short to intermediate times is governed by the dot-lead hybridization parameter ($\ensuremath{\Gamma}$) and by the typical Phonon frequency (${\ensuremath{\omega}}_{c}$) and depends on the location of the energy level of the dot relative to the bias window. At longer times, the dynamics shows a distinct behavior depending on whether the system is in the adiabatic or nonadiabatic regime, with a quantum dot occupation that may depend on the initial preparation of the Phonon degrees of freedom. A ``phase'' diagram of this effect as a function of the polaron shift ($\ensuremath{\lambda}$) for various Phonon frequencies is derived, suggesting the existence of bistability on experimentally observable time scales.
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bistability in a nonequilibrium quantum system with Electron Phonon Interactions
Physical Review B, 2013Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Guy Cohen, Eran RabaniAbstract:The existence of more than one steady state in a many-body quantum system driven out of equilibrium has been a matter of debate, both in the context of simple impurity models and in the case of inelastic tunneling channels. In this paper, we combine a reduced density matrix formalism with the multilayer multiconfiguration time-dependent Hartree method to address this problem. This allows us to obtain a converged numerical solution of the nonequilibrium dynamics. Considering a generic model for quantum transport through a quantum dot with Electron-Phonon interaction, we prove that a unique steady state exists regardless of the initial Electronic preparation of the quantum dot, consistent with the converged numerical results. However, a bistability can be observed for different initial Phonon preparations. The effects of the Phonon frequency and strength of the Electron-Phonon couplings on the nonequilibrium dynamics and on the emergence of bistability is discussed.
Michael Thoss - One of the best experts on this subject based on the ideXlab platform.
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sub ohmic to super ohmic crossover behavior in nonequilibrium quantum systems with Electron Phonon Interactions
Physical Review B, 2015Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:at zero temperature and zero bias, while for super-Ohmic ( s> 1) spectral densities this transition disappears. In this paper, we consider the influence of the Phonon-bath spectral density on the nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by the extended Holstein model. Using the reduced density matrix formalism combined with the multilayer multiconfiguration time-dependent Hartree approach, we investigate the dynamic response, the time scales for relaxation, as well as the existence of multiple long-lived solutions as the system-bath coupling changes from the sub- to the super-Ohmic cases. Bistability is shown to diminish for increasing powers of s similar to the spin-boson case. However, the physical mechanism and the dependence on the model parameters such as the typical bath frequency ωc and the polaron shift λ are rather distinct.
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sub ohmic to super ohmic crossover behavior in nonequilibrium quantum systems with Electron Phonon Interactions
Physical Review B, 2015Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The transition from weakly damped coherent motion to localization in the context of the spin-boson model has been the subject of numerous studies with distinct behavior depending on the form of the Phonon-bath spectral density $J\left(\ensuremath{\omega}\right)\ensuremath{\propto}{\ensuremath{\omega}}^{s}$. Sub-Ohmic ($sl1$) and Ohmic ($s=1$) spectral densities show a clear localization transition at zero temperature and zero bias, while for super-Ohmic ($sg1$) spectral densities this transition disappears. In this paper, we consider the influence of the Phonon-bath spectral density on the nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by the extended Holstein model. Using the reduced density matrix formalism combined with the multilayer multiconfiguration time-dependent Hartree approach, we investigate the dynamic response, the time scales for relaxation, as well as the existence of multiple long-lived solutions as the system-bath coupling changes from the sub- to the super-Ohmic cases. Bistability is shown to diminish for increasing powers of $s$ similar to the spin-boson case. However, the physical mechanism and the dependence on the model parameters such as the typical bath frequency ${\ensuremath{\omega}}_{c}$ and the polaron shift $\ensuremath{\lambda}$ are rather distinct.
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nonequilibrium quantum systems with Electron Phonon Interactions transient dynamics and approach to steady state
Physical Review B, 2014Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by a generalized Holstein model is presented. A combination of methodologies, including the reduced density matrix formalism, the multilayer multiconfiguration time-dependent Hartree method, and a time-dependent nonequilibrium Green’s function approach, is used to explore the transient behavior on multiple time scales as the system approaches steadystate.Thedotpopulationdynamicsonshorttointermediatetimesisgovernedbythedot-leadhybridization parameter (� ) and by the typical Phonon frequency (ωc) and depends on the location of the energy level of the dot relative to the bias window. At longer times, the dynamics shows a distinct behavior depending on whether the system is in the adiabatic or nonadiabatic regime, with a quantum dot occupation that may depend on the initial preparation of the Phonon degrees of freedom. A “phase” diagram of this effect as a function of the polaron shift (λ) for various Phonon frequencies is derived, suggesting the existence of bistability on experimentally observable time scales.
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nonequilibrium quantum systems with Electron Phonon Interactions transient dynamics and approach to steady state
Physical Review B, 2014Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by a generalized Holstein model is presented. A combination of methodologies, including the reduced density matrix formalism, the multilayer multiconfiguration time-dependent Hartree method, and a time-dependent nonequilibrium Green's function approach, is used to explore the transient behavior on multiple time scales as the system approaches steady state. The dot population dynamics on short to intermediate times is governed by the dot-lead hybridization parameter ($\ensuremath{\Gamma}$) and by the typical Phonon frequency (${\ensuremath{\omega}}_{c}$) and depends on the location of the energy level of the dot relative to the bias window. At longer times, the dynamics shows a distinct behavior depending on whether the system is in the adiabatic or nonadiabatic regime, with a quantum dot occupation that may depend on the initial preparation of the Phonon degrees of freedom. A ``phase'' diagram of this effect as a function of the polaron shift ($\ensuremath{\lambda}$) for various Phonon frequencies is derived, suggesting the existence of bistability on experimentally observable time scales.
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bistability in a nonequilibrium quantum system with Electron Phonon Interactions
Physical Review B, 2013Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Guy Cohen, Eran RabaniAbstract:The existence of more than one steady state in a many-body quantum system driven out of equilibrium has been a matter of debate, both in the context of simple impurity models and in the case of inelastic tunneling channels. In this paper, we combine a reduced density matrix formalism with the multilayer multiconfiguration time-dependent Hartree method to address this problem. This allows us to obtain a converged numerical solution of the nonequilibrium dynamics. Considering a generic model for quantum transport through a quantum dot with Electron-Phonon interaction, we prove that a unique steady state exists regardless of the initial Electronic preparation of the quantum dot, consistent with the converged numerical results. However, a bistability can be observed for different initial Phonon preparations. The effects of the Phonon frequency and strength of the Electron-Phonon couplings on the nonequilibrium dynamics and on the emergence of bistability is discussed.
Haobin Wang - One of the best experts on this subject based on the ideXlab platform.
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sub ohmic to super ohmic crossover behavior in nonequilibrium quantum systems with Electron Phonon Interactions
Physical Review B, 2015Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:at zero temperature and zero bias, while for super-Ohmic ( s> 1) spectral densities this transition disappears. In this paper, we consider the influence of the Phonon-bath spectral density on the nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by the extended Holstein model. Using the reduced density matrix formalism combined with the multilayer multiconfiguration time-dependent Hartree approach, we investigate the dynamic response, the time scales for relaxation, as well as the existence of multiple long-lived solutions as the system-bath coupling changes from the sub- to the super-Ohmic cases. Bistability is shown to diminish for increasing powers of s similar to the spin-boson case. However, the physical mechanism and the dependence on the model parameters such as the typical bath frequency ωc and the polaron shift λ are rather distinct.
-
sub ohmic to super ohmic crossover behavior in nonequilibrium quantum systems with Electron Phonon Interactions
Physical Review B, 2015Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The transition from weakly damped coherent motion to localization in the context of the spin-boson model has been the subject of numerous studies with distinct behavior depending on the form of the Phonon-bath spectral density $J\left(\ensuremath{\omega}\right)\ensuremath{\propto}{\ensuremath{\omega}}^{s}$. Sub-Ohmic ($sl1$) and Ohmic ($s=1$) spectral densities show a clear localization transition at zero temperature and zero bias, while for super-Ohmic ($sg1$) spectral densities this transition disappears. In this paper, we consider the influence of the Phonon-bath spectral density on the nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by the extended Holstein model. Using the reduced density matrix formalism combined with the multilayer multiconfiguration time-dependent Hartree approach, we investigate the dynamic response, the time scales for relaxation, as well as the existence of multiple long-lived solutions as the system-bath coupling changes from the sub- to the super-Ohmic cases. Bistability is shown to diminish for increasing powers of $s$ similar to the spin-boson case. However, the physical mechanism and the dependence on the model parameters such as the typical bath frequency ${\ensuremath{\omega}}_{c}$ and the polaron shift $\ensuremath{\lambda}$ are rather distinct.
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nonequilibrium quantum systems with Electron Phonon Interactions transient dynamics and approach to steady state
Physical Review B, 2014Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by a generalized Holstein model is presented. A combination of methodologies, including the reduced density matrix formalism, the multilayer multiconfiguration time-dependent Hartree method, and a time-dependent nonequilibrium Green’s function approach, is used to explore the transient behavior on multiple time scales as the system approaches steadystate.Thedotpopulationdynamicsonshorttointermediatetimesisgovernedbythedot-leadhybridization parameter (� ) and by the typical Phonon frequency (ωc) and depends on the location of the energy level of the dot relative to the bias window. At longer times, the dynamics shows a distinct behavior depending on whether the system is in the adiabatic or nonadiabatic regime, with a quantum dot occupation that may depend on the initial preparation of the Phonon degrees of freedom. A “phase” diagram of this effect as a function of the polaron shift (λ) for various Phonon frequencies is derived, suggesting the existence of bistability on experimentally observable time scales.
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nonequilibrium quantum systems with Electron Phonon Interactions transient dynamics and approach to steady state
Physical Review B, 2014Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Eran RabaniAbstract:The nonequilibrium dynamics of a quantum dot with Electron-Phonon Interactions described by a generalized Holstein model is presented. A combination of methodologies, including the reduced density matrix formalism, the multilayer multiconfiguration time-dependent Hartree method, and a time-dependent nonequilibrium Green's function approach, is used to explore the transient behavior on multiple time scales as the system approaches steady state. The dot population dynamics on short to intermediate times is governed by the dot-lead hybridization parameter ($\ensuremath{\Gamma}$) and by the typical Phonon frequency (${\ensuremath{\omega}}_{c}$) and depends on the location of the energy level of the dot relative to the bias window. At longer times, the dynamics shows a distinct behavior depending on whether the system is in the adiabatic or nonadiabatic regime, with a quantum dot occupation that may depend on the initial preparation of the Phonon degrees of freedom. A ``phase'' diagram of this effect as a function of the polaron shift ($\ensuremath{\lambda}$) for various Phonon frequencies is derived, suggesting the existence of bistability on experimentally observable time scales.
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bistability in a nonequilibrium quantum system with Electron Phonon Interactions
Physical Review B, 2013Co-Authors: Eli Y Wilner, Haobin Wang, Michael Thoss, Guy Cohen, Eran RabaniAbstract:The existence of more than one steady state in a many-body quantum system driven out of equilibrium has been a matter of debate, both in the context of simple impurity models and in the case of inelastic tunneling channels. In this paper, we combine a reduced density matrix formalism with the multilayer multiconfiguration time-dependent Hartree method to address this problem. This allows us to obtain a converged numerical solution of the nonequilibrium dynamics. Considering a generic model for quantum transport through a quantum dot with Electron-Phonon interaction, we prove that a unique steady state exists regardless of the initial Electronic preparation of the quantum dot, consistent with the converged numerical results. However, a bistability can be observed for different initial Phonon preparations. The effects of the Phonon frequency and strength of the Electron-Phonon couplings on the nonequilibrium dynamics and on the emergence of bistability is discussed.
Adam Roberts - One of the best experts on this subject based on the ideXlab platform.
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probing Electron Phonon Interactions at the saddle point in graphene
Frontiers in Optics, 2014Co-Authors: Adam Roberts, R Binder, Nai H Kwong, Dheeraj Golla, Daniel Cormode, Brian J Leroy, Henry O Everitt, Arvinder SandhuAbstract:High frequency differential transmission spectroscopy of graphene, probing near the M-point, is performed and analyzed theoretically. Electron-Phonon coupling is identified as the chief mechanism for renormalization with an effective acoustic deformation potential of approximately 5eV.
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optical characterization of Electron Phonon Interactions at the saddle point in graphene
Physical Review Letters, 2014Co-Authors: Adam Roberts, R Binder, Nai H Kwong, Dheeraj Golla, Daniel Cormode, Brian J Leroy, Henry O Everitt, Arvinder SandhuAbstract:The role of many-body Interactions is experimentally and theoretically investigated near the saddle point absorption peak of graphene. The time and energy-resolved differential optical transmission measurements reveal the dominant role played by Electron-acoustic Phonon coupling in band structure renormalization. Using a Born approximation for Electron-Phonon coupling and experimental estimates of the dynamic lattice temperature, we compute the differential transmission line shape. Comparing the numerical and experimental line shapes, we deduce the effective acoustic deformation potential to be ${D}_{\text{eff}}^{\text{ac}}\ensuremath{\simeq}5\text{ }\mathrm{eV}$. This value is in accord with recent theoretical predictions but differs from those extracted using electrical transport measurements.