2007 Fiscal Year Final Research Report Summary
Spin Manipulation of Coupled Spin Structures in Semiconductor Macro-atoms
| Project/Area Number |
18310074
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nanostructural science
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| Research Institution | NTT Basic Research Laboratories |
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Principal Investigator |
GOTOH Hideki NTT Basic Research Laboratories, NTT Basic Research Laboratories, Research Planning Section, Senior Research Scientist (10393795)
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| Co-Investigator(Kenkyū-buntansha) |
TATENO Kouta NTT Basic Research Laboratories, Optical Science Laboratory, Research Scientist (20393796)
SANADA Haruki NTT Basic Research Laboratories, Optical Science Laboratory, Researcher (50417094)
ZHANG Guoqiang NTT Basic Research Laboratories, Optical Science Laboratory, Research Associate (90402247)
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| Project Period (FY) |
2006 – 2007
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| Keywords | Nano-materials / Semiconductor Physics / Optical Properties |
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| Research Abstract |
We achieved the fabrication method of macro-atom samples for single spin manipulation and developed measurement techniques of these samples. Moreover, we created macro-atoms with semiconductor nano-wire structures.
As for the spin manipulation, we used GaAs/AlGaAs quantum well structures whose well widths were smaller than the exciton Bohr radius. We processed electrodes to pump electrons into the quantum wells and measured photoluminescence(PL) properties with the micro-PL method. In the measurement, very fine PL peaks were observed, which originate from localized excitons as well as localized charged excitons. We also found the method to efficiently create charged excitons and obtain highly polarized excitons. These results are fundamental requirements to manipulate single spins.
We observed very sharp PL peaks from semiconductor nano-wires including quantum dot structures in wires. Their propreties were very similar to those of conventional In GaAs quantum dots. We also found these na
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no-wires showed highly amsotropic PL properties. This proprety is due to the spatial symmetry of nano-wire samples. These results clearlyshow that the nano-wire fabrication technique can be applied to create macro-atom structures.
We fabricated various nano-wires to obtain best macro-atoms having good optical properties. Most of previous nano-wires used GaAs substrates. Whereas for our samples, Si substiates were used to fit to many conventional electronic devices. We grew GaP nano-wires and GaAs nano-wires on GaP wires. Both these wires show good PL propreties. Moreover, we developed to align GaP nano-wires employing the position controrlling technique of gold paiticle on Si surface. We also devised a method creating bended GaP structures having thin GaAs regions with an annealing technique. As for device structure, field effect transistors with InAs nano-wires were fabricated and clear transistor characteristics were confirmed at room temperature. Recently, we observed PL emission in telecommunication wavelength regions at room tempreature, which have not yet been repoited from other research groups.
In the near future, we will develop the concrete method to manipulate single spin and to control coupled spins in macro-atoms. Our result in this research term is the important milestones to proneer a new research field with macro-atoms physics and its device applications. Less
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