Controlled charge and spin current rectifications in a spin polarized device: Effect of dephasing

Quasicrystals have been the subject of intense research in the discipline of condensed matter physics due to their non-trivial characteristic features. We find surprisingly high degree of charge and spin current rectifications in a one-dimensional system with finite modulation is site energy and/or nearest-neighbor hopping (NNH) integrals in the form of well known Aubry-Andre or Harper (AAH) model. Each site of the chain is comprised a finite magnetic moment which is responsible for spin separation, and, in presence of finite bias an electric field is generated along the chain which essentially makes the asymmetric band structures under forward and reverse biased conditions, yielding finite rectification. Rectification is observed in two forms: (i) positive and (ii) negative, depending on the sign of currents in two bias polarities. These two forms can only be observed in the case of spin current rectification, while charge current shows conventional rectification operation. Moreover, we discuss how rectification ratio and especially its direction can be controlled by AAH phase which is always beneficial for efficient designing of a device. Finally, we examine the role of dephasing on rectification operations. Our study gives a new platform to analyze current rectification at nano-scale level, and can be examined in different quasi-crystals along with quantum Hall systems.