“…In the last decades, Schrödinger's idea stimulated numerous theoretical studies e.g. in ultracold atoms [3,4], semiconductors [5][6][7][8][9][10], carbon nanotubes [11], topological insulators [12], crystalline solids [13,14] and other systems [15][16][17][18]. Although ZBW was theoretically found using a quantum simulation of the Dirac equation for trapped ions [19], Bose-Einstein condensates [20][21][22] and, most recently, an optical simulation [23], up to now, no direct experimental observations have been carried out.…”