Browsing by Author "Akimoto, H."

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Observation of strong electron dephasing in highly disordered Cu93Ge4Au3 thin films
(2007-07-27)
Huang, S. M.
;
Lee, T. C.
;
Akimoto, H.
;
Kono, K.
;
Lin, J. J.
We report the observation of strong electron dephasing in a series of disordered Cu93Ge4Au3 thin films. A very short electron dephasing time possessing very weak temperature dependence around 6 K, followed by an upturn with further decrease in temperature below 4 K, is found. The upturn is progressively more pronounced in more disordered samples. Moreover, a lnT-dependent, but high-magnetic-field-insensitive, resistance rise persisting from above 10 K down to 30 mK is observed in the films. These results suggest a nonmagnetic dephasing process which is stronger than any known mechanism and may originate from the coupling of conduction electrons to dynamic defects.
Spin Bottleneck in Resonance Tunneling through In0.04Ga0.96As/GaAs Vertical Double Quantum Dots
(2011-01-01)
Huang, S. M.
;
Tokura, Y.
;
Akimoto, H.
;
Kono, K.
;
Lin, J. J.
We study the electron resonance tunneling through double quantum dots with different g factors. We found that the resonance tunneling current is suppressed even if one of the Zeeman sublevels is aligned. The level broadening effect partially releases the blockade. The current maximum peak appears when the interdot detune is half of Zeeman energy difference of two quantum dots.
Spin Bottleneck in Resonant Tunneling through Double Quantum Dots with Different Zeeman Splittings
(2010-04-02)
Huang, S. M.
;
Tokura, Y.
;
Akimoto, H.
;
Kono, K.
;
Lin, J. J.
We investigated the electron transport property of the InGaAs/GaAs double quantum dots, the electron g factors of which are different from each other. We found that in a magnetic field, the resonant tunneling is suppressed even if one of the Zeeman sublevels is aligned. This is because the other misaligned Zeeman sublevels limit the total current. A finite broadening of the misaligned sublevel partially relieves this bottleneck effect, and the maximum current is reached when interdot detuning is half the Zeeman energy difference.