2007 Fiscal Year Final Research Report Summary
Quantum transport in semiconductor superlattices in a tilted magnetic field
| Project/Area Number |
17540296
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics I
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| Research Institution | Osaka University |
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Principal Investigator |
MORI Nobuya Osaka University, Graduate School of Engineering, Associate Professor (70239614)
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| Project Period (FY) |
2005 – 2007
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| Keywords | superlattice / semiconductor / high magnetic field / quantum transport / chaos / non-eouilihrium / Landau level / Wannier-Stark quantization |
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| Research Abstract |
We have exploited the narrow energy miniband widths of a semiconductor SL (Δ < 〓ω_<LO>) and a strong quantizing magnetic field (Δ < 〓ω) to controllable increase the inelastic scattering time, τ. We have observed a universal suppression of current flow with increasing τ for SLs with different Δ, and a combined Stark-cyclotron-magnetophonon resonance effect. Our results demonstrate the intimate link between electronic conduction and inelastic mattering in a quasi-1D and -0D periodic potential, which is important for the design of devices based on artificial nanowires and quantum dot SLs.
We have also studied the dynamics of Bloch electrons in a semiconductor superlattice in the presence of an electric field F applied along the SL axis and pulsed magnetic fields B up to 47 T. For B applied along x, the current flow through the SL is reduced at all biases, and resonant peaks in the current-voltage characteristics are observed at values of F and B for which electron hopping between isoenergetic Wannier-Stark-Landau states in adjacent quantum wells is followed by intrawell resonant magnetophonon energy relaxation. We observed a pronounced change in the electron dynamics when B is tilted at an angle relative to x. A strong increase of the current is observed over an extended range of magnetic fields and applied biases. The transition between these two distinct regimes of electronic conduction can be explained within semiclassical and quantum-mechanical models. In a semiclassical description, for θ > 0°, the component of B perpendicular to x acts to ample the Bloch and cyclotron oscillatory motions, thus leading to extended electron trajectories. Within a quantum-mechanical model, this coupling lifts the degeneracy of the isoenergetic Wannier-Stark-Landau states and leads to a different type of magnetic-field-induced miniband made of states that maintain an extended-like character along x even at values of F normally associated with Wannier-Stark localization.
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[Journal Article] Magnetic-field-induced miniband conduction in semiconductor superlattices2007
Author(s)
D., Fowler, D.P. A., Hardwick, A., Patane, M.T., Greenaway, A.G., Balanov, T.M., Fromhold, L., Eaves, M., Henini, N., Kozlova, J., Freudenberger, N., Mori
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Journal Title
Physical Review B Vol.76, No.24
Pages: 245303(1-6)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Strong- effect of resonant impurities on Landau-level quantization2006
Author(s)
G., Allison, N., Mori, A., Patane, J., Endicott, L., Eaves, D. K., Maude, M., Hopkinson
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Journal Title
Physical Review Letters Vol.96
Pages: 236802(1-4)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Impurity cyclotron resonance in InGaAs/GaAs superlattice and InGaAs/AIAs superlattice grown on GaAs substrates2006
Author(s)
H., Momose, H., Okai, H., Deguchi, N., Mori, S., Takeyama
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Journal Title
Physica E Vol.32, No.1-2
Pages: 309-312
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Current flow and energy dissipation in low-dimensional semiconductor superlattices2006
Author(s)
D., Fowler, A., Patane, A., Ignatov, L., Eaves, M., Henini, N., Mori, D.K., Maude, R., Airey
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Journal Title
Applied Physics Letters Vol.88
Pages: 052111(1-3)
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Impurity cyclotron resonance in InGaAs/AIAs superlattice under ultra high magnetic fields2005
Author(s)
H., Momose, H., Deguchi, H., Okai, N., Mori, S., Takeyama
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Journal Title
Physica E Vol.29, No.3-4
Pages: 606-608
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Strong efect of resonant impurities on Landau level quantisation2006
Author(s)
G., Allison, N., Mori, A., Patane, J., Endicott, L., Eaves, D., Maude, M., Hopkison
Organizer
28th International Conference on the Physics of Semiconductors, ThM2b.2
Place of Presentation
Vienna, Austria
Year and Date
20060724-28
Description
「研究成果報告書概要(欧文)」より
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[Presentation] Electronic conduction in low-dimensional semiconductor superlattices2006
Author(s)
D., Fowler, A., Patane, L., Eaves, A., Ignatov, M., Henini, N., Mori, D.K., Maude, R., Airey
Organizer
28th International Conference on the Physics of Semiconductors, MoA2e.4
Place of Presentation
Vienna, Austria
Year and Date
20060724-28
Description
「研究成果報告書概要(欧文)」より
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