Collapse of electrons to a donor cluster inSrTiO3

Abstract

It is known that a nucleus with charge Ze, where Z > 170 creates electron-positron pairs from the vacuum. Electrons collapse onto the nucleus resulting in a net charge Zn < Z while the positrons are emitted. This effect is due to the relativistic dispersion law. The same reason leads to the collapse of electrons to the donor cluster with a large charge number Z in narrow-band gap semiconductors, Weyl semimetals and graphene. In this paper, a similar effect of electron collapse and charge renormalization is found for a donor cluster in SrTiO3 (STO), but with a different origin. At low temperatures, STO has an enormously large dielectric constant and the nonlinear dielectric response becomes dominant when the electric field is still small. This leads to the collapse of electrons into a charged spherical donor cluster with radius R when its total charge number Z exceeds a critical value Zc R/a where a is the lattice constant. The net charge Zne grows with Z until Z exceeds Z * (R/a) 9/7 . After this point, the charge of the compact core Zn remains Z * , while the rest Z * electrons form a sparse Thomas-Fermi electron atmosphere around it. We show that the thermal ionization of such two-scale atoms easily strips the outer atmosphere while the inner core remains preserved. We extend our results to the case of long cylindrical clusters. We discuss how our predictions can be tested by measuring conductivity of chain of discs of charge on the STO surface.

Fluctuations of Flow Harmonics in Pb+Pb Collisions at $\sqrt {s_{NN}}=2.76$ TeV from the Glauber Model

“…Our results for ellipticity and triangularity fluctuations agree qualitatively with the studies of Ref. [11,13,14], but correct the results of the Glauber simulations presented in Refs. [6,7] To reproduce the results of the simulations presented in this paper, or to extend them to other physical cases, the user should download the package GLISSANDO 2 ver.…”

“…It has been argued (see, e.g., Ref. [11,12,14,38]) that to a good accuracy one has the proportionality (the "shape-flow" transmutation) v n = κ n n , n = 2, 3,…”

“…While many such studies have been presented in the literature (see, e.g., the references in the recent review in Ref. [9], or the latest works [10,11,12,13,14,15]), recently some confusion has been raised by results published in Ref. [6,7] claiming, that the Glauber model fails badly for the fluctuations of flow (cf.…”

On the peripheral tube description of the two-particle correlations in nuclear collisions

“…It is interesting to compare the present model to the interpretation frequently employed in the literature, where random but systematic emergence of octupole deformation in the initial energy distribution is considered to lead to the final triangular flow, and consequently, the double peak nature of the two particle correlations in the final state. The mostly linear relation between the initial anisotropy parameters, ǫ n and the flow harmonics v n , observed in numerical simulations [32,[41][42][43] are considered as the evidence of such interpretation. We note that it is meaningful to compare the present model to another approach frequently employed in the literature, where the one-particle distribution are decomposed into different flow harmonics.…”

Universality of electron mobility in LaAlO3/SrTiO3 and bulk SrTiO3

“…Due to the relatively large width of this electron layer, we essentially deal with a three-dimensional system. 35,36 Such an electronic system can be described by the recent theory [37][38][39] of accumulation layers in STO based on a combination of the Landau-Ginzburg description of the dielectric response of the STO lattice and the Thomas-Fermi approximation for the degenerate electron gas. Using this theory, we show below that the three-dimensional electron density of the electronic system near the LAO/STO interface, n 3D , depends on the measured two-dimensional sheet electron density, n s , in the following way:…”