Probing spin ice in HoAgGe with a scanning tunneling microscope
Pairs of dips in tunneling spectra away from defects disappeared when the crystal warmed above its spin-ice ordering temperature.
The magnetic atoms of HoAgGe form a kagome lattice built from triangles. Using a scanning tunneling microscope, the team found pairs of dips in spectra taken away from defects, one at positive bias and one at negative bias.
The dips vanished when the crystal was warmed above its spin-ice ordering temperature. The authors interpreted them as local spin flips excited by tunneling electrons, offering an atomic-scale probe of the magnetic order. Liyuan Zhang at SUSTech is a coauthor of the Physical Review Letters paper.