Schematic representation of a junction contacted between two magnetic leads. The spin-valve effect can be triggered by some external magnetic field.
Schematic representation of electron hopping process controlled by the spin states of the molecular junction. From the wave-functions, the various quantities involved in the model are extracted and indicated.
(Up) normalized intensity as a function of the ramping voltage V for an unpolarized current. (Down) Schematic representation of the channels involved for each step with the corresponding structure of the wave-function. The parameters defining the junction spectroscopy are ε0 = −15 000 cm−1, t = −3000 cm−1, K = 10 cm−1, and U = 25 000cm−1. The peaks positions and their numbers are unchanged whatever the electrodes magnetizations. For a parallel situation, the relative heights of the peaks are constant. In contrast, the relative heights are functions of the electrodes magnetizations for antiparallel orientations (see Sec. II B ).
Magnetoresistance MR as a function of the left electrode magnetization x. The circled numbers indicate the steps for which the magnetoresistance is calculated. The black dashed-dotted line corresponds to the MR values in the absence of a contacted molecule.
Evolution of the MR value for x = 1 as a function of the μ/λ ratio. The circled numbers indicate the steps for which the magnetoresistance is calculated. The μ/λ ratio is equal to and goes to 1 in the U → ∞ limit. The vertical dotted line indicates the validity domain for monodeterminantal approaches. The heavy dash around 0.6 corresponds to the situation observed for our chosen set of parameters.
Simplified expression of the different coupling coefficients for the parallel situation.
Simplified expression of the different coupling coefficients for the antiparallel situation.
Article metrics loading...
Full text loading...