| Project/Area Number |
06640500
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
物性一般(含基礎論)
|
|---|
| Research Institution | The University of Tokyo |
|---|
Principal Investigator |
AOKI Hideo The University of Tokyo, Graduate School of Science, Associate Professor, 大学院・理学系研究科, 助教授 (50114351)
|
|---|
| Project Period (FY) |
1994 – 1995
|
| Project Status |
Completed (Fiscal Year 1995)
|
| Budget Amount *help |
¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1995: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
|
|---|
| Keywords | fractional quantum Hall effect / composite particle picture / strong correlation / spin degrees of freedom / double quantum well / quantum dot / 電子相関 |
|---|
| Research Abstract |
The purpose of the present project is to investigate versatile phases arising from spin and/or layr degrees of freedom in the fractional quantum Hall (FQH) system. In the 1995 fiscal year, we have focussed on the composite fermion picture for the double-layr FQH system. In a double system the strength of inter-layr tunnelling enters as a new energy scale.
We have found the following :
・ The composite fermion picture is a good approximation even for the excited states (pseudo-spin wave) in double-layr systems.
・ We can describe the double-layr FQH system with the phase diagram on the tunneling strength and the layr separation. The quantum Hall region is identified from a finite gap in the low-lying excitation (which is exactly the pseudo-spin wave). The composite picture has enabled us to obtaine for the first time the phase diagram for the fractional double-layr system. The quantum Hall region widens dramatically as the Landau-level filling degreases to 1/3,1/5, ..., which is due to the fact that the composite-particle transformation diminishes the interaction while keeping the tunnelling unchanged.
・ We have a vertically coupled double dot if we confine the electrons in a double-layr into quantum dots. We have proposed this system, and have shown that (i) there is a series of new magic numbers in the total angular momentum specific to double dots, and (ii) these magic numbers may be observed with the optical absorption.
|
