Shot noise in magnetic tunneling structures with two-level quantum dots

T. Szczepański, V. K. Dugaev, J. Barnaś, I. Martinez, J. P. Cascales, J.-Y. Hong, M.-T. Lin, and F. G. Aliev

Phys. Rev. B 94, 235429 – Published 22 December 2016

Abstract

We analyze shot noise in a magnetic tunnel junction with a two-level quantum dot attached to the magnetic electrodes. The considerations are limited to the case when some transport channels are suppressed at low temperatures. Coupling of the two dot's levels to the electrodes are assumed to be generally different and also spin dependent. To calculate the shot noise we apply the approach based on the full counting statistics. The approach is used to account for experimental data obtained in magnetic tunnel junctions with organic barriers. The experimentally observed Fano factors correspond to the super-Poissonian statistics, and also depend on relative orientation of the electrodes' magnetic moments. We have also calculated the corresponding spin shot noise, which is associated with fluctuations of spin current.

Received 20 August 2016
Revised 7 December 2016

DOI:https://doi.org/10.1103/PhysRevB.94.235429

Physics Subject Headings (PhySH)

Spintronics

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

T. Szczepański¹, V. K. Dugaev¹, J. Barnaś^2,3, I. Martinez⁴, J. P. Cascales^4,5, J.-Y. Hong⁶, M.-T. Lin^6,7, and F. G. Aliev⁴

¹Department of Physics and Medical Engineering, Rzeszów University of Technology, al. Powstańców Warszawy 6, 35-959 Rzeszów, Poland
²Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
³Institute of Molecular Physics, Polish Academy of Sciences, ul. M. Smoluchowskiego 17, 60-179 Poznań, Poland
⁴Departmento de Fisica de la Materia Condensada, C-III, IFIMAC and INC, Universidad Autonoma de Madrid, 28049, Madrid, Spain
⁵Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
⁶Department of Physics, National Taiwan University, 10617 Taipei, Taiwan
⁷Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand

Issue

Vol. 94, Iss. 23 — 15 December 2016

Reuse & Permissions

Access Options

Author publication services for translation and copyediting assistance advertisement

Physical Review B

covering condensed matter and materials physics