Surface and electronic structure at atomic length scales of the nonsymmorphic antiferromagnet Eu 5 In 2 Sb 6
We performed scanning tunneling microscopy and spectroscopy (STM/STS) measurements to investigate the Zintl phase Eu 5 In 2 Sb 6 , a nonsymmorphic antiferromagnet. The theoretical prediction of a nontrivial Fermi surface topology stabilized by the nonsymmorphic symmetry motivated our research. On the cleaved (010) plane, we obtained striped patterns that can be correlated to the stacking of the [In 2 Sb 6 ] 10- double chains along the crystallographic c axis. The attempted cleavage along the a axis revealed a more complex pattern. We combined the STS measurement on nonreconstructed (010) and (081) surfaces with DFT calculations to further elucidate the electronic structure of Eu 5 In 2 Sb 6 . From our investigations so far, direct experimental evidence of the predicted topological surface states remains elusive.