Spin-polarized Scanning Tunneling Microscopy

Antiferromagnetic spin-structure of reconstruced α-Mn deposited on Fe(100). The structure shows a compensated but non-collinear arrangement of spins at the surface (size 100x100 nm).

In spin-polarized Scanning Tunneling Microscopy (Sp-STM), the spin polarisation of the electron is mapped in parallel to the local density of states of a sample surface. This allows to link electronic densities and spin-polarisations, i.e. the two fundamental parameters of electronic states. Physical phenomena like ferromagnetism and antiferromagnetism become accessible on the atomic scale making Sp-STM the magnetic imaging technique of ultimate lateral resolution. In contrast to neutron scattering, it operates in real space and can be used to map even non periodic structures like defects and frustrations of the antiferromagnetic order.

We used Sp-STM to study the spin configuration of magnetic nano-structures and antiferromagnets on the atomic scale. Sp-STM is further used to learn about the basic phenomena of spin-polarised electron transport like tunneling magneto-resistance, spin blockade or electron magnon scattering.

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