Nonresonant Spectral Hole Burning in Liquids and Solids

Chamberlin, Ralph V.; Böhmer, Roland; Richert, Ranko

doi:10.1007/978-3-319-77574-6_5

Cited by 10 publications

(21 citation statements)

References 130 publications

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“…The study of the primary relaxation of supercooled liquids by means of dielectric techniques in the linear response regime is standard and allows investigations over an extremely broad frequency range [1,2,3]. Apart from the detailed form of the spectra the nature of the dynamical heterogeneities has been studied using various frequency-selective techniques [4,5,6,7], including higher-dimensional nuclear magnetic resonance experiments [8,9,10] and nonresonant dielectric hole-burning [11,12,13]. The latter techniques allow the frequencyselective modification of the spectrum via the application of strong electric fields.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear response theory for Markov processes. III. Stochastic models for dipole reorientations

Diezemann¹

2018

Phys. Rev. E

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The nonlinear response of molecular systems undergoing Markovian stochastic reorientations is calculated up to fifth order in the amplitude of the external field. Time-dependent perturbation theory is used to compute the relevant response functions as in earlier treatments (G. Diezemann, Phys. Rev. E85, 051502 (2012), Phys. Rev. E96, 022150 (2017)). Here, we consider the reorientational motion of isolated molecules and extend the existing calculations for the model of isotropic rotational diffusion to the model of anisotropic rotational diffusion and to the model of rotational random jumps. Depending on the values of some model parameters, we observe a hump in the modulus of the nonlinear susceptibility for either of these models. Interestingly, for the model of rotational random jumps, the appearance of this hump depends on the way the coupling to the external field is modelled in the master equation approach. If the model of anisotropic rotational diffusion is considered, the orientation of the diffusion tensor relative to the molecular dipole moment and additionally the amount of anisotropy in the rotational diffusion constants determine the detailed shape of the nonlinear response. In this case, the height of the observed hump is found to increase with increasing 'diffusional anisotropy'. We discuss our results in relation to the features observed experimentally in supercooled liquids. PACS: 64.70.Q-, 61.20.Lc, 05.40.-a 1 arXiv:1808.03188v2 [cond-mat.soft]

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Section: Introductionmentioning

confidence: 99%

Nonlinear response theory for Markov processes. III. Stochastic models for dipole reorientations

Diezemann¹

2018

Phys. Rev. E

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“…Thus, these intercellular interactions are added to bypass a basic constraint from assuming constant-volume cells, which can be avoided by using variable-volume regions in the nanocanonical ensemble. Our models for uncorrelated small subsystems inside macroscopic samples match the original theory of smallsystem thermodynamics, and mimic the measured primary response in most materials [36][37][38][39][40][41][42][43][44][45][46][47][48][49]. [17].…”

Section: An Introduction To Nanothermodynamicsmentioning

confidence: 68%

“…2), the fact that real gases do not show such deviations from the Sackur-Tetrode formula [69] implies ̅ ≫ 1; but any increase in entropy is favored by the second law of thermodynamics, and required by a fundamental property of quantum mechanics for sub-additive entropy [23,68]. Moreover, similarly uncorrelated small regions are found to dominate the primary response measured in liquids and solids [36][37][38][39][40][41][42][43][44][45][46][47][48][49].…”

Section: Figurementioning

confidence: 97%

“…Whereas several experimental techniques have shown that most primary degrees of freedom couple slowly to the heat reservoir, with energies that are persistently localized on time-scales of the primary response (e.g. 100 s to 100 μs) [36][37][38][39][40][41][42]. Furthermore, other techniques [43][44][45][46][47][48] have established that this localization involves regions with dimensions on the order of nanometers (e.g.…”

Section: Standard Statistical Mechanicsmentioning

confidence: 99%

“…canonical and grand-canonical), which restrict the exchange of some quantities but not others, are often artificially constrained. Specifically, because excess energy is persistently localized during the primary response in liquids, glasses, polymers, and crystals [36][37][38][39][40][41][42], sometimes for seconds or longer, particle exchange will usually accompany these slow changes in energy. Therefore, the relatively fast transfer of energy needed for a well-defined local temperature, without also changing size and particle number, is unlikely for the primary fluctuations inside most realistic systems.…”

Section: Entropy and Heat In An Ideal 1-d Polymermentioning

confidence: 99%

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Multiscale Thermodynamics: Energy, Entropy, and Symmetry from Atoms to Bulk Behavior

Chamberlin¹,

Clark²,

Mújica³

et al. 2021

Preprint

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Here we investigate how the local properties of particles in a thermal bath may influence the thermodynamics of the bath, and consequently alter the statistical mechanics of subsystems that comprise the bath. We are guided by the theory of small-system thermodynamics, which is based on two primary postulates: that small systems can be treated self-consistently by coupling them to an ensemble of similarly small systems, and that a large ensemble of small systems forms its own thermodynamic bath. We adapt this “nanothermodynamics” to investigate how a large system may subdivide into an ensemble of smaller subsystems, causing internal heterogeneity across multiple size scales. For the semi-classical ideal gas, maximum entropy favors subdividing a large system of “atoms” into an ensemble of “regions” of variable size. The mechanism of region formation could come from quantum exchange symmetry that makes atoms in each region indistinguishable, while decoherence between regions allows atoms in separate regions to be distinguishable by their distinct locations. Combining regions reduces the total entropy, as expected when distinguishable particles become indistinguishable, and as required by a theorem in quantum mechanics for sub-additive entropy. Combining large volumes of small regions gives the usual entropy of mixing for a semi-classical ideal gas, resolving Gibbs paradox without invoking quantum symmetry for atoms that may be meters apart. Other models presented here are based on Ising-like spins, which are solved analytically in one dimension. Focusing on the bonds between the Ising-like spins we find similarity in the equilibrium properties of a two-state model in the nanocanonical ensemble and a three-state model in the canonical ensemble. Thus, emergent phenomena may alter the thermal behavior of microscopic models, and the correct ensemble is necessary for fully-accurate predictions. Another result using Ising-like spins involves simulations that include a nonlinear correction to Boltzmann’s factor, which mimics the statistics of indistinguishable states by imitating the dynamics of spin exchange on intermediate lengths. These simulations exhibit 1/f-like noise at low frequencies (f), and white noise at higher f, similar to equilibrium thermal fluctuations found in many materials.

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Some open challenges in polymer physics*

McKenna

Chen

Mangalara

et al. 2022

Polymer Engineering & Sci

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Three subjects in polymer and soft matter physics are outlined in the present article. The first relates to concepts of an ideal glass transition. We describe work on ultra-stable glass, either a 20-million-year-old amber or a vapor deposited amorphous fluoropolymer, which examines the temperature dependence of the dynamics in a window between a low fictive temperature and the glass transition temperature. From this "finesse" of the problem of the geological time scales in sub-glass temperature systems strong evidence that the divergence of the relaxation times at finite temperature from WLF-types of extrapolation is not correct. The second topic is polymer nonlinear viscoelasticity as it relates to dynamic heterogeneity. We show results from mechanical hole burning experiments that suggest that dynamic heterogeneity arises from the nature of specific relaxation mechanisms rather than heterogeneous changes in, for example, the fictive temperature. Included is a discussion of large amplitude oscillatory shear testing and how it relates to characterization of nonlinear viscoelastic materials. The last topic addressed is the rheology of circular macromolecules. Here, we take a historical perspective and describe important new results from several laboratories that seem inconsistent. New works from our own studies on circular DNA are also discussed.

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Nonresonant Spectral Hole Burning in Liquids and Solids

Cited by 10 publications

References 130 publications

Nonlinear response theory for Markov processes. III. Stochastic models for dipole reorientations

Nonlinear response theory for Markov processes. III. Stochastic models for dipole reorientations

Multiscale Thermodynamics: Energy, Entropy, and Symmetry from Atoms to Bulk Behavior

Some open challenges in polymer physics*

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