This week in cond-mat

Slightly delayed because of the joys of grant proposals, here is this week's installment of my quasi-periodic snippets of things I find interesting on the arxiv preprint server....


cond-mat/0603598 - Siemons et al., Origin of the unusual transport properties observed at hetero-interfaces of LaAlO3 on SrTiO3
This paper is interesting for a couple of reasons. First, the author list includes some luminaries in the field, including Ted Geballe, Mac Beasley, and Walt Harrison. They're all extremely nice guys, and Walt literally wrote the book(s) on electronic structure calculation methods. It's great that these folks are not just still active, but really pushing new ground, at a point in their careers when many full professors decide to kick back. Second, this paper reports data on a relatively new material system, a heterojunction between two oxide materials. Like the GaAs/AlGaAs case, the conduction band offset between the two materials leads to the formation of a potential well right at the interface, so that electrons can be trapped there in a two-dimensional layer. This result studies electronic transport in those layers, and tries to address the question of where the free carriers come from, given that the materials are ideally not doped.

cond-mat/0603482 - Pickett, Design for a room temperature superconductor
Bonus points for the provocative title. This paper (part of a commemorative volume in honor of Vitaly Ginzburg), looks at MgB2, a superconductor that is not a copper oxide, but nonetheless has a transition temperature of nearly 40 K, and tries to argue from that material what would be necessary to have (phonon-mediated) room temperature superconductivity. Thought provoking, and with references to good MgB2 literature for those interested in how that material was discovered to superconduct at the shockingly recent date of 2001.