Collective Excitations in the Antisymmetric Channel of Raman Spectroscopy

1. Front Matter

   Pages i-xvi

   PDF

2. Introduction

   • Hsiang-Hsi Kung

   Pages 1-22

3. Experimental Setup

   • Hsiang-Hsi Kung

   Pages 23-40

4. Raman Scattering in URu2Si2

   • Hsiang-Hsi Kung

   Pages 41-93

5. Secondary Emission in Bi2Se3

   • Hsiang-Hsi Kung

   Pages 95-148

6. Conclusion

   • Hsiang-Hsi Kung

   Pages 149-151

This thesis contains three breakthrough results in condensed matter physics. Firstly, broken reflection symmetry in the hidden-order phase of the heavy-fermion material URu2Si2 is observed for the first time. This represents a significant advance in the understanding of this enigmatic material which has long intrigued the condensed matter community due to its emergent long range order exhibited at low temperatures (the so-called “hidden order”). Secondly and thirdly, a novel collective mode (the chiral spin wave) and a novel composite particle (the chiral exciton) are discovered in the three dimensional topological insulator Bi2Se3. This opens up new avenues of possibility for the use of topological insulators in photonic, optoelectronic, and spintronic devices. These discoveries are facilitated by using low-temperature polarized Raman spectroscopy as a tool for identifying optically excited collective modes in strongly correlated electron systems and three-dimensional topological insulators.  

• URu2Si2
• Bi2Se3
• heavy-fermion material
• dirac fermion
• spin-orbit coupling
• Raman spectroscopy
• chiral spin mode
• hidden order
• antiferromagnetic phase

• Quantum Matter Institute, University of British Columbia, Vancouver, Canada

  Hsiang-Hsi Kung

Hsiang-Hsi (Sean) Kung is a postdoctoral researcher at the Quantum Matter Institute at the University of British Columbia. He received his PhD from Rutgers University in 2018.

Policies and ethics