Thang Pham, Postdoc Fellow, Superconducting Quantum Materials and Systems (SQMS) Northwestern University

Different classes of quantum materials abound with rich correlated physics in the bulk form, such as superconductivity, magnetism and more recently, topological states; but many of them are virtually unexplored in the reduced-dimension structures. Specific classes of nanostructured quantum materials of great interest are two-dimensional van der Waals (vdW) magnet and atomically thin single chains of one-dimensional vdW materials. In the first part of my talk, I will introduce an environmentally stable 2D vdW magnet, CrSBr, which allows us to explore its atomic structure by scanning transmission electron microscopy (S/TEM). I will then present an electron-beam irradiation method to manipulate the defect formation and consequently to design the spin texture in the material. In the second part of my talk, I will present my recent efforts in isolation and study of a single chain of 1D vdW materials encapsulated within carbon and boron nitride nanotubes, by the combination of aberration-corrected S/TEM and density functional theory, exemplified by the discovery of torsional instability and helical structural wave in few-to-single chain of charge-density wave NbSe₃