The Energy States of Single Quantum-Dot Molecules in Magnetic Fields
CHANG WEN HAO
|關鍵字:||量子點;量子點分子;顯微螢光光譜;quantum dots;quantum-dot molecules;μ-PL|
並探討QDM 在磁場作用下的能態耦合現象。探討議題包括g 值的操控、輕-重電洞
This project is proposed to study the coupled energy states of single quantum-dot molecules (QDM) formed by single pairs of vertically coupled In(Ga)As quantum dots (QDs). The topics to be studied include: (1) The mechanism of exciton energy transfer in single QDMs and (2) The coupling effects of energy states in single QDMs under the influence externally applied magnetic field. Time-resolved micro-photoluminescence (μ-PL) will be employed to study the dynamics of exciton transfer in single QDMs at different temperatures. The feasibility of selective excitation of exciton states in single QDMs will be explored by μ-PL excitation spectroscopy. In addition, we will also set up an optical system to conduct polarization-resolved photon correlation measurements for the study of underlying dark exciton states involved in biexciton-exciton cascade emission processes in single QDMs. Magneto-μ-PL spectroscopy with external applied magnetic field up to B= 6 T in either Faraday or Vogit configurations can be utilized to measure the diamagnetic shift and Zeeman splitting in single QDs and QDMs. By these measurements, the impact of dot size, shape as well as non-uniformly strain field distribution on the g factor will also be discussed. The magnetic field induced coupling in energy states of single QDMs will also be investigated. The manipulation of g factor, valence band mixing between heavy-hole and light-hole states, as well as the mixing between bright and dark exciton states under the influence of external applied magnetic field will be discussed.
|Appears in Collections:||Research Plans|