Imaging real-space flat band localization in kagome magnet FeSn

Discrete flat-band solitons in the kagome lattice

Flat-band excitonic states in Kagome lattice on semiconductor surfaces

Recent surface techniques to fabricate and arrange quantum wires on the semiconductor surface have enabled to synthesize the artificial two-dimensional lattice systems such as square and triangle lattices. For example, C. Albrecht et al. produced a square lattice by arranging InAs wires on GaInAs (001) surface and showed that a butterfly energy spectra is seen in the case of applying the magnet...

Topological excitations in a kagome magnet.

Chirality--that is, left or right handedness--is present in many scientific areas, and particularly in condensed matter physics. Inversion symmetry breaking relates chirality with skyrmions, which are protected field configurations with particle-like and topological properties. Here we show that a kagome magnet, with Heisenberg and Dzyaloshinskii-Moriya interactions, causes non-trivial topologi...

Bosonic Condensation and Disorder-Induced Localization in a Flat Band.

We report on the engineering of a nondispersive (flat) energy band in a geometrically frustrated lattice of micropillar optical cavities. By taking advantage of the non-Hermitian nature of our system, we achieve bosonic condensation of exciton polaritons into the flat band. Because of the infinite effective mass in such a band, the condensate is highly sensitive to disorder and fragments into l...

Thermal Hall Effect of Spin Excitations in a Kagome Magnet.

At low temperatures, the thermal conductivity of spin excitations in a magnetic insulator can exceed that of phonons. However, because they are charge neutral, the spin waves are not expected to display a thermal Hall effect. However, in the kagome lattice, theory predicts that the Berry curvature leads to a thermal Hall conductivity κ(xy). Here we report observation of a large κ(xy) in the kag...