Detection of spin change directly in the total magnetoconductance of mesoscopic systems using controllable impurity:...

The total Zeeman and Rashba magnetoconductances (G=G↑↑+G↑↓) in quantum wire, quantum point contact and open quantum dot, they do not naturally display spin changes (flipping and polarizations) in the line form, especially at the perturbative limit; this was only observed theoretically in the contributions (spin conductances):G↑↑andG↑↓. Here in this work, we study the possibility of directly observing the induced spin changes in the total magnetoconductance (perturbative limit), which would be an important tool for monitoring the spin in electron magnetotransport experiments. Using three-dimensional magnetoconductance,G(ϕ/ϕo,E), with locally applied Zeeman or Rashba effects (defined with an extensionL), we are able to detect spin changes directly in the total conductance, using variations ofLin conjunction with the application of a controllable impurity. Here using electrons with spin up, as incident electrons, the spin change (spin flipping) is observed whenG↑↓becomes dominant, generating Fabry-Pérot type ripples in the total conductance,G. These ripples are associated with asymmetries in the spin contributions, induced by the controllable impurity. This controllable impurity reveals spin changes (high up or down polarizations) through asymmetries detected in the induced ripples. Theϕ/ϕonumber of flux quanta in the limit studied here is used only to couple to the spin change generator and also to make the signatures better defined. The signatures studied here are also observed forϕ/ϕo=0.