Shot noise of a ferromagnetic nanowire with a domain wall

We study shot noise of the spin-polarized current in a diffusive ferromagnetic nanowire which contains a ballistic domain wall. We find that the existence of a short domain wall influences strongly the shot noise for sufficiently high spin polarization of the wire. Compared to the situation of the absence of the domain wall, the shot noise can be reduced or enhanced depending on the length of the domain wall and its relative conductance.

Figure 1

(Color online) (a) Schematic of a nanowire containing a domain wall and (b) the corresponding circuit model of the nanowire.

Figure 2

(Color online) (a) Conductance of the ferromagnetic nanowire with a domain wall relative to its conductance without domain wall and (b) the Fano factor of the nanowire, in terms of the domain wall length for different values of $2E_F/h_0$ and $g_0/g_F=80$. Inset in (b) shows the minimum of the Fano factor.

Figure 3

(Color online) Fano factor of the ferromagnetic nanowire with a domain wall for three values of $g_0/g_F$ and $2E_F/h_0$.