The interplay of strain, pressure, superconductivity, and topology in Weyl semimetal MoTe2
"Topological classification of materials has revolutionized condensed matter physics over the last decade and lead to a vast array of predicted novel technologies relying on topological electronic states. The search for novel topological semimetals and superconductors is particularly interesting, and the transition metal dichalcogenides are promising hosts of these states. Intrinsic to developing new technologies from topological electronic states is the ability to control and engineer the materials systems that house these states. The transition metal dichalcogenide MoTe2 is a fascinating system with a coexistence of superconductivity, Weyl nodes, and a polar crystal structure where chemical doping, dimensionality, electric field, strain, pressure, and temperature all act to couple and tune between this rich array of electronic and crystal structures. I will present our work to correlate and differentiate between pressure and strain control of crystal symmetry, topology, and superconductivity using a complementary combination of transport, neutron scattering, and first-principles calculations. In particular, I will illustrate how structural phase transition dynamics and microstructure influence the measured electronic ground state and can lead to emergent quantum behavior in a structurally disordered system. "
Bio:
Colin Heikes is a NRC Postdoctoral Fellow at the NIST Center for Neutron Research (NCNR), focusing on structure and magnetism in strongly correlated materials and quantum materials such as complex oxides and transition metal dichalcogenides. Colin received his B.S. in Materials Science and Engineering from UMD in 2008, and his PhD in Materials Science and Engineering from Cornell University in May 2015. While at Cornell, Colin studied low temperature magneto-optical properties of complex oxides and two-dimensional systems like transition metal dichalcogenides, as well as the growth of complex oxide thin-films and heterostructures using reactive oxide molecular beam epitaxy. Colin’s current research interests focus on the interplay between strain and interface engineering in multiferroic thin films, as well as the importance of ground state nuclear structure and defects to emergent quantum ground states in correlated electron materials.