Hund's flat band in a frustrated spinel oxide. - Oh D; Hampel A; Wakefield JP; Moen PC; Smit S; Luo X; Zonno M; Gorovikov S; Leandersson M; Polley C; Kundu AK; Rajapitamahuni A; et al. (Proceedings of the National Academy of Sciences of the United States of America, 2025)