Investigation into the Eu Based 122 Family of Magnetic Topological Candidates*

Incorporating additional quantum phases such as magnetism into topological materials can open the door to new and advanced quantum technology. This research highlights the new intrinsic magnetic topological quantum material candidate, EuMg2Bi2. Magnetic susceptibility measurements performed by ORNL indicate that EuMg2Bi2 orders antiferromagnetically at T_N = 8.2 K. To further investigate the electronic behavior, ARPES data was performed in collaboration with Brookhaven National Laboratory (BNL) and confirmed the surface state of EuMg2Bi2 to be similar to the observed type II nodal line semimetal Mg3Bi2 previously determined in our group. Recently, neutron scattering measurements revealed EuMg2Bi2 to exhibit an A-type magnetic structure, which is consistent with the work reported here. In order to gain further insight into the potential coupling between the magnetism and topological states, the magnetic behavior and topology was considered for multiple materials related to EuMg2Bi2. From this research an in-depth discussion of the magnetic behavior, design and prediction of Eu based 122 materials has been realized.