Role of asymmetric magnetic electrodes in tuning spin selective rectification action of borazine [B3N3H6]

- We report on emergence of multifunctional activity (simultaneous exhibition of spin filtration) appearing due to asymmetry in anchor group and magnetic-nonmagnetic electrode combination in simple [B3N3H6].
- Interestingly, Equilibrium Spin Filter Efficiency (ESFE) as reported with magnetic Ni (0 0 1) is as high as 85%; however same reduces to 70% and 40% in case of two different combinations of Fe (1 0 0) electrode. Multifunctionality such as simultaneous exhibition of spin filtration and spin rectification, is only observed with Au(1 1 1)-S-B3N3H6-S-Fe(1 0 0).
- Transmission spectra obtained at zero bias and at two optimum voltages explains the multifunctional activity in Au(1 1 1)-S-B3N3H6-S-Fe(1 0 0). Pictorial representation of transmission pathways across central region of the two-probe system under considerations, quite clearly decipher the prospective multifunctional behavior of thiol-ended gold iron combinations.
- The zero bias Projected device density of states analysis establishes that d-orbital of Ni or Fe is responsible of electron tunneling across the Fermi level.
- A molecular origin of transmission spectra has been provided by examining Molecular projected self consistent Hamiltonian (MPSH) states associated with all three two-probe systems under investigation. Highly delocalized equilibrium MPSH states obtained with down spin channel are the origin of the observed spin filter actions amongst all three systems. However, spin selective rectification action is made by similar analysis performed at two terminal voltages ±1 V.

Herein, we examine the role of magnetic and non-magnetic electrodes and molecule-electrode anchor group in inducing simultaneous exhibition of spin filtration and rectification action in borazine. Magnetic electrodes preferred are iron and nickel; where as non-magnetic electrode used is gold; with anchor group varying from thiol ended molecule on either end to that at only one end. Two-probe systems developed, manifests large equilibrium spin filter efficiency (85%) with gold-nickel combinations, however dual nature of spin filtration and rectification is profusely evident with gold-iron combinations with thiol ended electrode-molecule contact on either end. Results obtained, have been explained through the transmission spectra obtained at equilibrium and ±1 V. A molecular level explanation has been provided through the analysis of molecular projected Hamiltonian states obtained at equilibrium and ±1 V. These results along with projected device density states analysis establish the role of d orbital of nickel or iron in inducing the observed feature.

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