Rigidity and Superfast Signal Propagation in Fluids and Solids in Non-Equilibrium Steady States
| Autor: | Kirkpatrick, T. R., Belitz, D., Dorfman, J. R. |
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| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | J. Phys. Chem. B 125, 7499 (2021) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1021/acs.jpcb.0c11283 |
| Popis: | In the 1980s it was theoretically predicted that correlations of various observables in a fluid in a non-equilibrium steady state (NESS) are extraordinarily long-ranged, extending, in a well-defined sense, over the size of the system. This is to be contrasted with correlations in an equilibrium fluid, whose range is typically just a few particle diameters. These NESS correlations were later confirmed by numerous experimental studies. Unlike long-ranged correlations at critical points, these correlations are generic in the sense that they exist for any temperature as long as the system is in a NESS. In equilibrium systems, generic long-ranged correlations are caused by spontaneously broken continuous symmetries and are associated with a generalized rigidity, which in turn leads to a new propagating excitation or mode. For example, in a solid, spatial rigidity leads to transverse sound waves, while in a superfluid, phase rigidity leads to temperature waves known as second sound at finite temperatures, and phonons at zero temperature. More generally, long-ranged spatial correlations imply rigidity irrespective of their physical origin. This implies that a fluid in a NESS should also display a type of rigidity and related anomalous transport behavior. Here we show that this is indeed the case. For the particular case of a simple fluid in a constant temperature gradient, the anomalous transport behavior takes the form of a super-diffusive spread of a constant-pressure temperature perturbation. We also discuss the case of an elastic solid, where we predict a spread that is faster than ballistic. Comment: 9pp, 2 figs |
| Databáze: | arXiv |
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