Mobility of a Small Polaron at Low Temperatures

Gogolin, A. A.

doi:10.1002/pssb.2221030144

Cited by 12 publications

(4 citation statements)

References 11 publications

(6 reference statements)

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“…For a given dimensionality, the interaction time is also reduced by increasing the strength of the intermolecular forces hence, the phonon dispersion. Consistently also the crossover temperature between band-like motion (at low T ) and hopping motion (at high T ) [79] shifts upwards, along the T axis, in higher dimensional systems with larger coordination numbers. Hopping polaron motion is the relevant transport mechanism in several systems including DNA chains [80,81].…”

Section: Introductionsupporting

confidence: 58%

Polaron Mass and Electron-Phonon Correlations in the Holstein Model

Zoli

2010

Advances in Condensed Matter Physics

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The Holstein Molecular Crystal Model is investigated by a strong coupling perturbative method which, unlike the standard Lang-Firsov approach, accounts for retardation effects due to the spreading of the polaron size. The effective mass is calculated to the second perturbative order in any lattice dimensionality for a broad range of (anti)adiabatic regimes and electron-phonon couplings. The crossover from a large to a small polaron state is found in all dimensionalities for adiabatic and intermediate adiabatic regimes. The phonon dispersion largely smooths such crossover which is signalled by polaron mass enhancement and on site localization of the correlation function. The notion of self-trapping together with the conditions for the existence of light polarons, mainly in two-and three-dimensions, are discussed. By the imaginary time path integral formalism I show how non local electron-phonon correlations, due to dispersive phonons, renormalize downwards the e-ph coupling justifying the possibility for light and essentially small 2D Holstein polarons.

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Section: Introductionsupporting

confidence: 58%

Polaron Mass and Electron-Phonon Correlations in the Holstein Model

Zoli

2010

Advances in Condensed Matter Physics

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“…The study of polaron properties has become a significant branch in condensed matter physics after Landau introduced the concept of an electron which can be trapped by digging its own hole in an ionic crystal. 1 Since then, several investigations [2][3][4][5][6][7][8][9][10][11][12][13] have analyzed the conditions under which polarons can form, their extension in real and momentum space, and the features of their motion both in physical 14 and biological 15,16 systems. While in general a sizable electronphonon coupling is a requisite for polaron formation, also the dimensionality and degree of adiabaticity of the physical system could essentially determine the stability and behavior of the polaronic quasiparticle.…”

Section: Introductionmentioning

confidence: 99%

Lattice-dynamics effects on small-polaron properties

Zoli

2000

Phys. Rev. B

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This study details the conditions under which strong-coupling perturbation theory can be applied to the molecular crystal model, a fundamental theoretical tool for analysis of the polaron properties. I show that lattice dimensionality and intermolecular forces play a key role in imposing constraints on the applicability of the perturbative approach. The polaron effective mass has been computed in different regimes ranging from the fully antiadiabatic to the fully adiabatic. The polaron masses become essentially dimension independent for sufficiently strong intermolecular coupling strengths and converge to much lower values than those traditionally obtained in small-polaron theory. I find evidence for a self-trapping transition in a moderately adiabatic regime at an electron-phonon coupling value of Ӎ3. Our results point to a substantial independence of the self-trapping event on dimensionality.

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“…In the strong-coupling regime the Lang-Firsov approach [23] is reliable [24,25] and the polaron mass m * can be obtained via a perturbative method. In d dimensions the ratio between m * and the bare band mass m 0 is [20] m…”

Section: The Holstein Model Hamiltonianmentioning

confidence: 99%

Polaron self-trapping in a honeycomb net

Zoli¹

2001

J. Phys.: Condens. Matter

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Small polaron behavior in a two dimensional honeycomb net is studied by applying the strong coupling perturbative method to the Holstein molecular crystal model. We find that small optical polarons can be mobile also if the electrons are strongly coupled to the lattice. Before the polarons localize and become very heavy, there is infact a window of e-ph couplings in which the polarons are small and have masses of order ≃ 5−50 times the bare band mass according to the value of the adiabaticity parameter. The 2D honeycomb net favors the mobility of small optical polarons in comparison with the square lattice.

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Mobility of a Small Polaron at Low Temperatures

Cited by 12 publications

References 11 publications

Polaron Mass and Electron-Phonon Correlations in the Holstein Model

Polaron Mass and Electron-Phonon Correlations in the Holstein Model

Lattice-dynamics effects on small-polaron properties

Polaron self-trapping in a honeycomb net

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