自旋池作用下量子点结构中的负微分热导效应

Negative differential of the heat generation effect in a quantum dot with spin bias

研究与双极自旋池连接的单能级量子点中自旋极化流的生热性质,发现通过适当调整自旋池中不同自旋方向电子的化学势,能够出现显著的负微分热导现象,即随着自旋压的增大,热流强度变小.还发现自旋极化流的生热性质对系统的温度不敏感,而自旋流与自旋压的曲线随温度的增加变得平滑,即声子辅助的电子隧穿过程被电子的热运动所破坏.

We study the heat generation by spin-polarized current due to the electron-phonon coupling in a single-level quantum-dot,which is connected to an external symmetric spin battery.We find that the heat generation depends sensitively on the configuration of the spin battery＇s chemical potentials.There is remarkable negative differential of the heat generation.We also find that the heat generation is insensitive to the system＇ s temperature,but the curve of spin current versus spin bias becomes smoother with increasing temperature,indicating that the phonon-assisted electron tunneling is suppressed by the electron thermal motion.