Topological Materials

Dirac cones are ubiquitous to non-trivial quantum matter and are expected to boost and reshape the field of modern electronics. Particularly relevant examples where these cones arise are topological insulators and graphene.

Dirac cones are ubiquitous to non-trivial quantum matter and are expected to boost and reshape the field of modern electronics. Particularly relevant examples where these cones arise are topological insulators and graphene.

This ​thesis reports a major breakthrough in discovering the superconducting mechanism in CeCoIn5, the “hydrogen atom” among heavy fermion compounds. By developing a novel theoretical formalism, the study described herein succeeded in extracting the crucial missing element of superconducting pairing interaction from scanning tunneling spectroscopy experiments. This breakthrough provides a theoretical explanation for a series of puzzling experimental observations, demonstrating that strong magnetic interactions provide the quantum glue for unconventional superconductivity.

This thesis focuses on the exploration of nontrivial spin dynamics in graphene-based devices and topological materials, using realistic theoretical models and state-of-the-art quantum transport methodologies. The main outcomes of this work are: (i) the analysis of the crossover from diffusive to ballistic spin transport regimes in ultraclean graphene nonlocal devices, and (ii) investigation of spin transport and spin dynamics phenomena (such as the (quantum) spin Hall effect) in novel topological materials, such as monolayer Weyl semimetals WeTe2 and MoTe2.

This ​thesis reports a major breakthrough in discovering the superconducting mechanism in CeCoIn5, the “hydrogen atom” among heavy fermion compounds. By developing a novel theoretical formalism, the study described herein succeeded in extracting the crucial missing element of superconducting pairing interaction from scanning tunneling spectroscopy experiments. This breakthrough provides a theoretical explanation for a series of puzzling experimental observations, demonstrating that strong magnetic interactions provide the quantum glue for unconventional superconductivity.

This compact undergraduate textbook provides a concise yet thorough introduction to the fundamentals of solid-state physics, while also briefly discussing the historical context surrounding key scholars in the field. The vivid explanations and unique didactic approach adopted in the book aim to generate interest in these subjects while also serving as a motivating primer and supporting companion for studying more detailed and advanced textbooks in solid-state physics. The book is also suitable as a quick refresher for students preparing for examinations.

This book presents the observation and the control of spin-polarized electrons in Rashba thin films and topological insulators, including the first observations of a weak topological insulator (WTI) and a higher-order topological insulator (HOTI) in bismuth halides. It begins with a general review of electronic structures at the solid surface and mentions that an electron spin at a surface is polarized due to the Rashba effect or topological insulator states with strong spin-orbit coupling.

This book presents the most important advances in the class of topological materials and discusses the topological characterization, modeling and metrology of materials. Further, it addresses currently emerging characterization techniques such as optical and acoustic, vibrational spectroscopy (Brillouin, infrared, Raman), electronic, magnetic, fluorescence correlation imaging, laser lithography, small angle X-ray and neutron scattering and other techniques, including site-selective nanoprobes. The book analyzes the topological aspects to identify and quantify these effects in terms of topology metrics.