MSE is pleased to announce that Jakob Hammond-Renfro, a physics major in the Goldman group, won first place (undergraduate division) in the poster competition at the American Society of Mechanical Engineers (ASME) International Mechanical Engineering Congress & Exposition (IMECE) 2025 in Memphis.

Hammond-Renfro was recognized for his research, “Probing the Electronic States of Antimony Telluride Homologous Superlattices," which he explains in more detail below.

Antimony telluride homologous superlattices are promising candidates for realizing novel electronic states, with significant implications for classical and quantum computing. My research involves scanning tunneling microscopy and spectroscopy (STM/S) studies of the antimony telluride homologous superlattice series (Sb₂Te₃)m(Sb₂)n, which is composed of alternating m-layers of Sb₂Te₃ and n-layers of Sb₂. Here, we report on a transition from semiconducting to semimetallic behavior as Sb₂ layers are introduced. In addition, we identify a “saddle point” in the energy dispersion, with sharp peaks in the density of energy states confirming the presence of a so-called Van Hove singularity that moves towards the Fermi level as n is increased. These findings demonstrate the potential for antimony telluride homologous superlattices to provide a platform for further studies of emergent quantum phenomena generated by strongly interacting electrons.

This work is a collaborative effort between several groups in the Center for Materials Innovation, the Materials Research Science and Engineering Center at U-M.

Congratulations, Jakob!