UCLA

Disorders and dissipations play the key role in the understanding of quantum coherent system. In this thesis, I'm using numeric method plus theoretical analysis to answer the questions: What are the low energy modes in disordered quantum spin system? How will environment dissipation damp the spin system's quasi-particle excitation quantitatively?

There are three parts in my thesis. Part 1 is the study of disordered quantum Ising chain. Part 2 is a numerical method for analytic continuation. Part 3 is the study of dissipative quantum Ising chain.