physica status solidi is devoted to the thorough peer review and the rapid publication of new and important results in all fields of solid state and materials physics, from basic science to applications and devices. Being among the largest and most important international publications, the pss journals publish review articles, letters and original work as well as special issues and conference contributions. physica status solidi (RRL) - Rapid Research Letters was designed to offer extremely fast publication times and is currently the fastest peer-reviewed publication medium in solid state physics. With submission numbers rising, editorial priority handling maintains the median turnaround time for editorial decisions at 14 days, and at 4 days from acceptance to online publication of the typeset and proof-read Letter. It communicates important findings with a high degree of novelty and need for express publication, as well as other results of immediate interest to the solid state physics and materials science community. Published Letters require approval by at least two independent referees.