Optical engineering of nuclear spins and localized spin manipulation

2016 Fiscal Year Final Research Report

• Project/Area Number: 25247047
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: Hokkaido University
• Principal Investigator: ADACHI Satoru 北海道大学, 工学研究院, 教授 (10221722)
• Project Period (FY): 2013-05-31 – 2017-03-31
• Keywords: 量子ドット / 核スピン / キャリアスピン / 核磁場制御

Outline of Final Research Achievements

In this research project, we aimed to establish the methods for optical engineering of nuclear spins in a single quantum dot structure. The following experimental achievements are especially important;
1. Even without any external magnetic field, the positive trion excited by the circularly-polarized light generated an Overhauser field of up to 0.8 T. From the excitation power dependences of the Overhauser field and degree of circular polarization of the photoluminescence spectra, the relation between the Overhauser field and Knight field under zero external magnetic field was revealed clearly.
2. we found a gradual reduction by almost one-order of the nuclear depolarization rate by increasing the longitudinal magnetic field up to 1 T. The change in the nuclear depolarization rate seemed to be related to the quadrupolar interaction with the tilted principal axis, and this observation can be interpreted as the restoring of the eigenaxis of nuclear spin.

Free Research Field

半導体スピン物性