Detecting chiral edge states in the Hofstadter optical lattice.

摘要: We propose a realistic scheme to detect topological edge states in an optical lattice subjected synthetic magnetic field, based on generalization of Bragg spectroscopy sensitive angular momentum. demonstrate that using well-designed laser probe, the spectra provide unambiguous signature establishes their chiral nature. This is present for variety boundaries, from hard wall smooth harmonic potential added top lattice. Experimentally, signal should be very weak. To make it detectable, we introduce ``shelving method,'' Raman transitions, which transfers momentum and changes internal atomic state simultaneously. allows us weak selected dark background, drastically improves detectivity. It also leads possibility directly visualize states, situ imaging, offering unique instructive view insulating phases.