Tricritical Dynamics at the Demixing-λ-Transition in 3He-4He Mixtures

Autor:	G. Moser, Reinhard Folk
Rok vydání:	2008
Předmět:	Physics Loop (topology) Tricritical point Zero (complex analysis) General Materials Science Statistical physics Renormalization group Condensed Matter Physics Kinetic energy Thermal diffusivity Constant (mathematics) Critical exponent Atomic and Molecular Physics and Optics
Zdroj:	Journal of Low Temperature Physics. 150:689-709
ISSN:	1573-7357 0022-2291
DOI:	10.1007/s10909-007-9605-5
Popis:	We calculate in two loop order the dynamical critical behavior at the tricritical point occuring in 3He-4He mixtures. Model F′ introduced by Siggia and Nelson (Phys. Rev. B 15:1427, [1977])—already problematic in one loop order—is shown in two loop order to lead to a divergence of the mass diffusion D in contradiction to experiments. Within the complex symmetric version of this model (model E⋆′) the dynamical critical exponents of the kinetic coefficients can be calculated exactly leading to a mass diffusion going to zero at the tricritical point as D(tX)∼tX1/2 (tX is the relative temperature distance at constant concentration) and the thermal diffusion ratio kT∼tX−1 diverges proportional to the concentration susceptibility in the experimental region. We also discuss effective dynamical critical exponents and compare them with recent simulations of the vector Blume-Emery-Griffths model.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::23ced571e162f5c4a66984d9d0697e7f https://doi.org/10.1007/s10909-007-9605-5 Zobrazit plný text záznamu Full text from SpringerLink