Scientific Achievement
A new method that precisely measures the magnetic properties of electrons flowing across the surface of a topological insulator reveals the correlation of electron momentum and spin polarization.
Significance and Impact
The ability to directly measure the spin potential of moving electrons results in a “spin voltmeter.” These measurements are crucial for evaluating spintronic and other quantum materials.
Research Details
- A spin-polarized four-probe scanning tunneling microscope is developed.
- This capability leads to the first direct revelation of spin-momentum locking in topological insulators.
- The current’s spin polarization is measured by comparing the potential difference acquired by a ferromagnetic and a nonmagnetic probe at the same sample location.
S. M. Hus, X.-G. Zhang, G. D. Nguyen, W. Ko, A. P. Baddorf, Y. P. Chen, A.-P. Li. Phys. Rev. Lett., 119, 137202 (2017). DOI: 10.1103/PhyRevLett.119.137202
