Photon-Assisted Heat Generation by Electric Current in a Quantum Dot Attached to Ferromagnetic Leads
Feng Chi1**, Lian-Liang Sun2
1School of Electronic and Information Engineering, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan 528400 2College of Science, North China University of Technology, Beijing 100041
Abstract：Heat generated by electric current in a quantum dot device contacting a phonon bath is studied using the non-equilibrium Green function technique. Spin-polarized current is generated owing to the Zeeman splitting of the dot level. The current's strength and the spin polarization are further manipulated by changing the frequency of an applied photon field and the ferromagnetism on the leads. We find that the associated heat by this spin-polarized current emerges even if the bias voltage is smaller than the phonon energy quanta and obvious negative differential of the heat generation develops when the photon frequency exceeds that of the phonon. It is also found that both the strength and the resonant peaks' position of the heat generation can be tuned by changing the value and the arrangement configurations of the magnetic moments of the two leads, and then provides an effective method to generate large spin-polarized current with weak heat. Such a result may be useful in designing low energy consumption spintronic devices.
. [J]. 中国物理快报, 2016, 33(11): 117201-117201.
Feng Chi, Lian-Liang Sun. Photon-Assisted Heat Generation by Electric Current in a Quantum Dot Attached to Ferromagnetic Leads. Chin. Phys. Lett., 2016, 33(11): 117201-117201.
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2016, Vol. 33 
