Indications for sharp continuous phase transitions at finite temperatures connected with the apparent metal-insulator transition in two-dimensional disordered systems

dc.creatorMobius, A.
dc.date2007-12-06
dc.date2008-05-05
dc.date.accessioned2026-07-07T09:39:32Z
dc.date.available2026-07-07T09:39:32Z
dc.descriptionIn a recent experiment, Lai et al. [Phys. Rev. B 75, 033314 (2007)] studied the apparent metal-insulator transition (MIT) of a Si quantum well structure tuning the charge carrier concentration $n$. They observed linear temperature dependences of the conductivity $σ(T,n)$ around the Fermi temperature and found that the corresponding $T \to 0$ extrapolation $σ_0(n)$ exhibits a sharp bend just at the MIT. Here, reconsidering the data published by Lai et al., it is shown that this sharp bend is related to a peculiarity of $σ(T=const.,n)$ clearly detectable in the whole $T$ range up to 4 K, the highest measuring temperature in that work. Since this peculiarity seems not to be smoothed out with increasing $T$ it may indicate a sharp continuous phase transition between the regions of apparent metallic and activated conduction to be present at finite temperature. Hints from the literature of such a behavior are discussed. Finally, a scaling analysis illuminates similarities to previous experiments and provides understanding of the shape of the peculiarity and of sharp peaks found in $d log_{10} σ/ d n (n)$.
dc.descriptionRevised version (quantitative determination of exponent beta added), accepted for publication by Physical Review B. Revtex, 10 pages, 9 figures
dc.identifierhttps://arxiv.org/abs/0712.0992
dc.identifierhttp://arxiv.org/abs/0712.0992
dc.identifierPhys. Rev. B 77, 205317 (2008)
dc.identifierdoi:10.1103/PhysRevB.77.205317
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/161203
dc.subjectStrongly Correlated Electrons
dc.subjectDisordered Systems and Neural Networks
dc.titleIndications for sharp continuous phase transitions at finite temperatures connected with the apparent metal-insulator transition in two-dimensional disordered systems
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