title: Study on spin and optical polarization in a coupled InGaN/GaN quantum well and quantum dots structure.
abstract: The spin and optical polarization based on a coupled InGaN/GaN quantum well (QW) and quantum dots (QDs) structure is investigated. In this structure, spin-electrons can be temporarily stored in QW, and spin injection from the QW into QDs via spin-conserved tunneling is enabled. Spin relaxation can be suppressed owing to the small energy difference between the initial state in the QW and the final states in the QDs. Photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurements are carried out on optical spin-injection and -detection. Owing to the coupled structure, spin-conserved tunneling mechanism plays a significant role in preventing spin relaxation process. As a result, a higher circular polarization degree (CPD) (~49.1%) is achieved compared with conventional single layer of QDs structure. Moreover, spin relaxation time is also extended to about 2.43 ns due to the weaker state-filling effect. This coupled structure is believed an appropriate candidate for realization of spin-polarized light source.
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Jiadong
authors.initials: J
authors.lastname: Yu
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Lai
authors.initials: L
authors.lastname: Wang
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.lastname: Di Yang
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Jiyuan
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Yuchen
authors.initials: Y
authors.lastname: Xing
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Zhibiao
authors.initials: Z
authors.lastname: Hao
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Changzheng
authors.initials: C
authors.lastname: Sun
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Han
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Xiong
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Li