2007 Fiscal Year Final Research Report Summary
Theory of Manipulation of Quantum System by Use of Nonadiabatic Quantum Phase
| Project/Area Number |
18540323
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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 Prefecture University |
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Principal Investigator |
KAYANUMA Yosuke Osaka Prefecture University, GRADUATE SCHOOL OF ENGINEERING, Professor (80124569)
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| Project Period (FY) |
2006 – 2007
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| Keywords | qubit / nonadiabatic transition / Landau-Zener formula / driven quantum system / phase interference / quantum heat bath / circuit QED / Lie algebra |
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| Research Abstract |
(1) We proposed a method of manipulation of qubit by use of correlated Landau-Zener tunneling, in which the interference effect of transition paths between the two nonadiabatic level-crossings gives rise to desired unitary transformations.
(2) An exact expression of the survival probability is obtained for a class of multi-level crossing problem. The formal perturbation expansion technique has been used successively to get the analytical result. The obtained formula has been applied to the analysis of the level-crossing problem under the effect of environment composed of phonons or spins.
(3) The internal relationship between the coherent destruction of tunneling (CDT) and the dynamic localization (DL) has been made clear by the Lie algebraic model. The two-state dynamics is mapped on the dynamics of the two-mode Schwinger boson model. The DL is interpreted as an infinitely large dimensional representation of the CDT in the operator level.
(4) The recent development in the study of the Landau-Zener-like model is reviewed in the light of advances in nano technologies and quantum dynamics.
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