Materials discovery requires new tools that enable design principles. Notable examples are the recent advances in topological materials due to insights from the interplay of topology and symmetry. We are investigating pseudospin control as a materials design tool for the discovery new magnetic states and superconductivity. The concept of pseudospin describes the two-fold Kramers degeneracy of Bloch electrons that arises at each momentum point k when the product of time-reversal T and inversion I symmetries is present. Normally, this pseudospin behaves as spin-1/2 under rotations, which drives much of our understanding of quantum materials, including Cooper pairing in superconductors, Stoner ferromagnetism, and the control of spin by Zeeman fields. Our recent work, however, shows that for crystals with non-symmorphic space group symmetry, the pseudospin can behave very differently than the usually spin-1/2, and can drive novel magnetic states, including altermagnets and odd-parity multipole magnets, and can qualitatively alter the superconducting response to magnetic fields.less in
The research, carried out by a collaboration between University of Wisconsin – Milwaukee and West Virginia University, to utilize pseudospin control as a new paradigm for materials discovery is carried out within the collaborative and iterative closed-loop framework outlined in the Materials Genome Initiative strategic plan, by combining analytic and predictive computational theory with experimental molecular beam epitaxy growth and characterization with in situ scanning tunneling microscopy/spectroscopy and angle-resolved photoemission spectroscopy, as well as ex-situ magneto- optical and electrical transport measurements.
This research is supported by the Designing Materials to Revolutionize and Engineer our Future (DMREF) program of the National Science Foundation (DMREF-2323857).
