Superpoissonian shot noise in organic magnetic tunnel junctions
Abstract
Organic molecules have recently revolutionized ways to create new spintronic devices. Despite intense studies, the statistics of tunneling electrons through organic barriers remains unclear. Here we investigate conductance and shot noise in magnetic tunnel junctions with PTCDA barriers a few nm thick. For junctions in the electron tunneling regime, with magnetoresistance ratios between 10 and 40\%, we observe superpoissonian shot noise. The Fano factor exceeds in 1.5-2 times the maximum values reported for magnetic tunnel junctions with inorganic barriers, indicating spin dependent bunching in tunneling. We explain our main findings in terms of a model which includes tunneling through a two level (or multilevel) system, originated from interfacial bonds of the PTCDA molecules. Our results suggest that interfaces play an important role in the control of shot noise when electrons tunnel through organic barriers.
Keywords
Cite
@article{arxiv.1501.05454,
title = {Superpoissonian shot noise in organic magnetic tunnel junctions},
author = {Juan Pedro Cascales and Jhen-Yong Hong and Isidoro Martinez and Minn-Tsong Lin and Tomasz Szczepanski and Vitalii K. Dugaev and Jozef Barnas and Farkad G. Aliev},
journal= {arXiv preprint arXiv:1501.05454},
year = {2015}
}