Spin Waves and magnetic exchange interactions in insulating Rb${}_{0.89}$Fe${}_{1.58}$Se${}_2$

Miaoyin Wang, Chen Fang, Dao-Xin Yao +10

The discovery of alkaline iron selenide $A$Fe${}_{1.6+x}$Se${}_2$ ($A=$ K, Rb, Cs) superconductors has generated considerable excitement in the condensed matter physics community becau…