Browsing by Author "Liao, Y. Y."

Now showing 1 - 4 of 4

Decoherence of a charge qubit embedded inside a suspended phonon cavity
(2008-01-01)
Liao, Y. Y.
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Chen, Y. N.
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Chou, W. C.
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Chuu, D. S.
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電子物理學系
This study elucidates the theory of phonon-induced decoherence of a double dot charge qubit that is embedded inside a suspended semiconductor slab. The influences of the lattice temperature, width of the slab, and positions of the dots on the decoherence are analyzed. Numerical results indicate that the decoherence in the slab system is weaker than that in a bulk environment. In particular, the decoherence is markedly suppressed by the inhibition of the electron-phonon coupling. Such a system with low decoherence may be useful for manipulating the qubits.
Electric-field-controlled electron relaxation in lateral double quantum dots embedded in a suspended slab
(2008-11-15)
Liao, Y. Y.
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Chuu, D. S.
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Jian, S. R.
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電子物理學系
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Department of Electrophysics
This study investigates phonon-induced electron relaxation in a lateral double quantum dot that is embedded in a suspended slab. Exact calculations are made in electric fields. The dependence of the relaxation rate on the parameters of the dots and the slabs is analyzed. Numerical results indicate that the relaxation rate depends strongly on the phonon character of the slab. Unlike in the bulk environment, phonon-subband quantization clearly influences the behavior. In particular, the relaxation rate can be greatly suppressed or enhanced by tuning the electric fields. This fact may be useful in manipulating the relaxation rate in lateral double quantum dots.
Electron transport of a driven three-level system in an asymmetric double quantum dot irradiated by an external field
(2007-03-01)
Liao, Y. Y.
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Chuu, D. S.
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Chen, Y. N.
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電子物理學系
;
Department of Electrophysics
Electron tunneling through a three-level system in an asymmetric double quantum dot irradiated by an external field is investigated. For a resonant external field, two symmetric peaks occur in the current spectrum. If the field frequency is detuned, unequal contributions from two channels lead to two asymmetric peaks with population inversion, which can be observed with increasing Rabi frequency. On the other hand, as the ground states in two dots are equal, a suppression of current occurs around the resonant frequency. In contrast, an enhanced behavior is found for the case of unequal ground states.
Insight of stress effect on the ONO stack layer in a SONOS-type flash memory cell
(2006)
Yeh, C. C.
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Liao, Y. Y.
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Wang, Tahui
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Tsai, W. J.
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Lu, T. C.
The stress effect on the ONO stack layer in a two-bit SONOS-type memory cell is investigated. Our results show that P/E cycles induced stress will generate extra nitride, oxide, and interface traps in the ONO stack layer. Besides, these stress created traps are unstable and will be annealed by additional thermal treatment. Storage electrons escape from stress-created nitride and oxide traps and the trap annealing effects are root causes of charge loss in a SONOS cell.