Citation:
Park JT, Friemel G, Loew T, Hinkov V, Li Y, Min BH, Sun DL, Ivanov A, Piovano A, Lin CT, et al. Similar zone-center gaps in the low-energy spin-wave spectra of Na 1-δFeAs and BaFe 2As 2. Physical Review B - Condensed Matter and Materials Physics. 2012;(2).