“…Exciton-polaritons also exhibit a significant nonlinearity, which in theory was predicted to itself induce topological behavior [97], antichiral behavior [215], non-Hermitian bi-skin e↵ect [228], and topological solitons [196]. Separate from topological physics, nonlinearity was shown to provide low-energy polaritonic switches [3,7,8], reservoir networks [229][230][231][232], artificial life [233], and realize other information processing elements such as transistors [3][4][5][6], routers [216][217][218], and amplifiers [9,10]. The possible use of topological polariton states at the edges of a strip to couple these elements su↵ers however from an obvious drawback: such states come in pairs, which propagate in opposite directions on the opposite edges of the strip [94,96].…”