Observation of topologically protected bound states in photonic quantum walks
Takuya Kitagawa, Matthew A. Broome, Alessandro Fedrizzi, Mark Spencer Rudner, Erez Berg, Ivan Kassal, Alán Aspuru‐Guzik, Eugene Demler, Andrew G. White · 2011
The authors study the topological properties of such a system: a modified version of the canonical discrete-time quantum walk on a line. The authors use a previously demonstrated photonic setup to implement a split-step quantum walk, as shown in the paper. The quantum walker is encoded in the orthogonal polarization components of heralded single photons, which we created via spontaneous parametric downconversion.