Small anisotropy of the lower critical field and $s_{\pm }$-wave two-gap feature in single crystal LiFeAs

Yoo Jang Song, Jin Soo Ghim, Jae Hyun Yoon +5

The in- and out-of-plane lower critical fields and magnetic penetration depths for LiFeAs were examined. The anisotropy ratio ${\gamma }_{H_{c1}}(0)$ is smaller than the expected theoretic…