پديدآورندگان :
Sadeghi Nastaran Iran, sadeghi_ns@yahoo.com 1Instructor, Department of Civil Engineering, Kashmar Branch, Islamic Azad University, Kashmar , Shahtahmassebi Nasser Department of Physics, Ferdowsi University of Mashhad, Mashhad, Iran , Ketabi S.Ahmad School of Physics, Damghan University, Damghan, Iran , Abolhassani Mohammad Reza Department of Physics, Science and Research Branch, Islamic Azad University, Tehran, Iran
كليدواژه :
Nano , Spintronics , Spin , filtering , Polaron , poly , BIPO.
چكيده فارسي :
The spin filtering ability of a model lead/poly-BIPO/lead junction is investigated. A polaron excitation is considered at the center of polymer. Four polaron types are assumed as the spin and charge density distributions. The Su-Schrieffer-Heeger Hamiltonian is modified by Hubbard and Heisenberg Hamiltonians to include the spin and charge interactions. The density of states, total current, spin-oriented currents and spin-polarization ability of the system in presence and absence of polaron excitations are studied. Calculations show that the complete spin-polarization for both of excited and non-excited systems is possible and over a voltage range it is a 100% plato. However, this voltage range is different for the excited and non-excited systems and in presence of polarons, it depends on polaron type. The current calculations predict that in presence of polaron excitations the spin-oriented current is enhanced. Also the excited energy states of polarons depend on polaron type. However it seems that for polarons with opposite spin and charge, the similar excited states have almost the same energy.
