Spin transfer enhancement and switching behavior in exchange bias spin valves

Spin transfer from polarized conduction electrons to the free layer’s magnetic moment is considerably enhanced when the fixed layer of a spin valve is magnetically pinned by an exchange bias antiferromagnet. This enhancement leads to significantly lower threshold current densities for spin transfer magnetization switching and to much higher total current induced effective fields. The phase diagram is not symmetric as in non-exchange biased spin valves but asymmetric over the field axis.