arXiv subjects

David M. -T. Kuo

Publications and source records attributed to David M. -T. Kuo.

21 records · Page 2Linked to original sources

arXiv2005

Interdot Coulomb repulsion effect on the charge transport of parallel double single electron transistors

The charge transport behaviors of parallel double single electron transistors (SETs) are investigated by the Anderson model with two impurity levels. The nonequilibrium Keldysh Green's technique is used to calculate the current-voltage characteristics of system. For SETs implemented by quantum dots (QDs) embedded into a thin $SiO_2$ layer, the interdot Coulomb repulsion is more important than the interdot electron hopping as a result of high potential barrier height between QDs and $SiO_2$. We found that the interdot Coulomb repulsion not onlyleads to new resonant levels, but also creates negative differential conductances.

cond-mat.mtrl-sci↗

arXiv2002

Effects of electron correlation on the photocurrent in quantum dot infrared photodetectors

The effect of electron correlation on the photocurrent of self-assembled InAs/InGaAs quantum dot infrared photo-detector (QDIPs) is studied. It is found that Coulomb interaction and level mixing in the many-body open system lead to double peaks associated with the intra-band transitions involving two lowest levels of the quantum dot. Furthermore, the photocurrent is a nonlinear function of the steady-state carrier density and it displays a plateau due to Coulomb blockade.

cond-mat.mes-hall↗

arXiv2002

Spontaneous spin polarized tunneling current through a quantum dot array

We show theoretically that a strongly spin-polarized current can be generated in semiconductors by taking advantage of the ferromagnetic phase of a quantum dot array (QDA). A Hubbard model with coupling to leads is used to study the tunneling current of the QDA system as a function of gate voltage. Due to the weak interdot coupling and strong Coulomb repulsion, it is found that a ferromagnetic phase exists in QDA within a window of gate voltage. Therefore QDA can be used as a spin filter to detect and control spin states in quantum information devices.

cond-mat.mes-hall↗