Li, PenggangYang, RongcaoXu, Zhiyong2015-12-101539-3755http://hdl.handle.net/1885/63462We predict the existence of gray (dark) solitary waves in negative-index materials on the basis of a derived higher-order nonlinear Schrödinger equation. The conditions for the formation of three cases of gray solitary waves and exact analytical expressiKeywords: Analytical expressions; Dinger equation; Higher order; Negative index material; Nonlinear effect; Solitary wave; Solitary wave solution; Metamaterials; Nonlinear equations; Solitons201010.1103/PhysRevE.82.0466032016-02-24