Tuesday, June 26, 2007

This week in cond-mat

Two good review articles in the last week appeared on cond-mat....

arxiv:0706.3015 - Bibes et al., Oxide spintronics
This is a nice overview of recent developments in using transition metal oxides, which often exhibit strong electronic correlations, for measurements and devices involving spin. This includes materials like the manganites (colossal magnetoresistance oxides), half-metals (magnetite, CrO2), magnetically doped oxides (TiO2, ZnO) as wide-band gap dilute magnetic semiconductors, and new multiferroic materials (ferroelectricity + magnetic order all wrapped up in one system). Good stuff.

arxiv:0706.3369 - Saminadayar et al., Equilibrium properties of mesoscopic quantum conductors
Despite being rendered in some species of pdf that my viewer finds nearly unreadable, this is a very nice article all about equilibrium quantum effects in nanostructures comparable in size to the electronic phase coherence length. This includes persistent currents in small metal and semiconductor loops. These persistent currents (flowing without dissipating!) result in part from the requirement that the electronic phase be single-valued when traversing a loop trajectory in a coherent manner. The persistent currents are very challenging to measure, and as far as I know there continues to be controversy about whether the magnitude and sign of the resulting magnetic moments is consistent with theory.

1 comment:

Anonymous said...

Thanks for pointing out Bibes & Barthelemy, I printed it for my train ride!

- The theoretician who thinks that it's experimentalists who publish such a lot.