UC Berkeley

Condensed matter physics today stands at the forefront of exploring unusual emergent material properties and exotic phenomena. At UC Berkeley, my research has been driven by a fundamental question: Can we engineer fundamental properties of novel organic quantum materials to address real-world problems? I believe the answer to this question lies at the intersection of various fundamental disciplines. In chemistry, my focus has been developing on-surface reactions that enable the assembly of unprecedented chemical structures, giving access to exotic materials with uncommon electronic structures. These synthetic innovations have been translated into developing organic quantum materials with unique properties in condensed matter physics.

In Part 1 of this dissertation, we start with the tight-binding approximation and density functional theory to illustrate the theoretical principles for constructing organic quantum materials (Chapter 1). We then focus on the carbon material system under investigation, examining the quantum confinement effect in Chapter 2, followed by an introduction to the scanning tunneling microscope that we used in this research.

In Part 2, we present several successful examples of constructing novel organic quantum materials based on the theoretical and instrumental background from Part 1. To this end, we have developed the low-dimensional N-heterocyclic carbene lattices, utilizing the frontier orbital to engineer one-dimensional to two-dimensional low-workfunction materials (Chapter 4). Additionally, we have employed orbital engineering concepts to construct a Dirac nodal-line semimetal in a dual-square covalent-organic framework (Chapter 5). The final example in Chapter 6 discusses the spontaneous symmetry-breaking Jahn-Teller distortion effect in an unconventional π-conjugated polymer.