Electron transport in parallel quantum wires with random potentials

Abstract

We study an electron transport property in two parallel quantum wires with random potentials. Assuming the same microscopic parameters for both wires, we focus on the relationship between inter-wire interaction and electron backward scattering by random potentials at low energy regime. Our analytical and numerical calculations show that the Drude weight, a measure of the electron transport, is influenced by inter-wire interaction and random potential independently, and little coupling between those two is observed, which is in contrast to a deep relationship between up- and down-spin interactions and random potentials in a single wire. It leads to that inter-wire interactions do not have a great influence on the Anderson localization in each wire.Comment: 4 pages, 1 figures, submitted to Phys. Rev. B, using REVTEX

Role of Embedded Clustering in Dilute Magnetic Semiconductors: Cr Doped GaN

“…1(e)]. Our findings are consistent with experimental work which shows that there is a significant N 2p-Cr 3d hybridization and that the material is semiconducting [22].…”

Paramagnetism and antiferromagnetic interactions in Cr-doped GaN

“…In the absence of p-holes to mediate p-d Zener exchange, our results show that the magnetic behavior of Cr 3+ (3d 3 ) is very similar to that of Mn 2+ (3d 5 ): short-ranged AFM interactions, which, as for Mn 2+ , are likely to result from indirect superexchange mediated by the N 2p band. Indeed, the necessary hybridization of the Cr 3d and N 2p states has also been observed [51,50].…”

“…This understanding of the magnetic interactions between Mn impurities in GaN in different charge states provides a good framework to interpret our results in the Cr-doping case. Chromium is incorporated in GaN as Cr 3+ (3d 3 ) [50,51], with only a donor level (3+/4+) in the bandgap [59]. In the absence of p-holes to mediate p-d Zener exchange, our results show that the magnetic behavior of Cr 3+ (3d 3 ) is very similar to that of Mn 2+ (3d 5 ): short-ranged AFM interactions, which, as for Mn 2+ , are likely to result from indirect superexchange mediated by the N 2p band.…”

“…Co-doped ZnO [23,24]. To model this behavior, we assume that all Cr impurities randomly occupy Ga sites [31,50,51] and that only isolated Cr atoms, i.e. without Cr nearest cation neighbors in the Ga sublattice, effectively contribute to the magnetization.…”

Reduction of lattice thermal conductivity of pseudogap intermetallic compound Al3V

“…Although Al-based compounds would be non-toxic and earth-abundant TE materials, these TE properties have been scarcely investigated. Some Al-based materials have narrow bandgaps (e.g., RuAl 2 [10]) or pseudogaps (e.g., Al 82.6-x Re 17.4 Si x [11], Fe 2 VAl [12,13]), and the Fermi level is located at the steeply descending part of the density of states (DOS). In general, a sharp increase in the DOS enhances S according to Mott's theory, [14] and the residual DOS support the high s. This is why some Al-based materials have high values of S 2 s, also called the power factor (PF).…”