Author : Robert Conner Walko
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (135 download)
Book Synopsis An Investigation of Materials at the Intersection of Topology and Magnetism Using Scanning Tunneling Microscopy by : Robert Conner Walko
Download or read book An Investigation of Materials at the Intersection of Topology and Magnetism Using Scanning Tunneling Microscopy written by Robert Conner Walko and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Material systems that combine magnetism and topology have garnered intense interest recently due to predictions of a variety of phenomena such as the quantum anomalous Hall effect, chiral topological edge states, magnetoelectric effects, and Weyl semimetal and axion insulator phases. In this dissertation scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) are used to investigate the structural and electronic properties of several materials that exist at the intersection of topology and magnetism such as topological insulators, van der Waals layered materials, two-dimensional magnets, and intrinsic magnetic topological insulators. Specifically, STM was used to confirm the growth quality and properties of thin films grown by molecular beam epitaxy including Bi2Se3, SnSe2, MnSe, and Fe3GeTe2. In the van der Waals heterostructure SnSe2/Bi2Se3 a moiré pattern was observed which was found to be correlated to a set of localized electronic states in STS measurements. STM was also used to provide feedback for the growth of the heterostructure MnSe/Bi2Se3, which led to successful growth of partial monolayers of MnSe. In Fe3GeTe2, a magnetic field dependent Kondo lattice behavior was observed as well as a ferromagnetic hysteresis loop using spin-polarized STM. In addition, this work reports the first STM study of the recently experimentally verified intrinsic antiferromagnetic topological insulator (AFM TI) MnBi2Se4. Its atomic and layered properties are found to reasonably match theoretical predictions. Two different terminations of its layered structure are observed on the surface with distinct electronic properties. In-gap states are observed near some step edges which could be related to predicted topological edge states. Another AFM TI, the related material MnBi2Te4, was also studied in which nanoscale surface manipulation using an STM tip was demonstrated.