أرسل هذا في رسالة قصيرة: Topological interface state formation in an hourglass lattice sandwich meta-structure

 _    _     ______   _    _     _____     ______  
| \  / ||  /_   _// | |  | ||  |  ___||  /_   _// 
|  \/  ||   -| ||-  | |/\| ||  | ||__      | ||   
| .  . ||   _| ||_  |  /\  ||  | ||__     _| ||   
|_|\/|_||  /_____// |_// \_||  |_____||  /__//    
`-`  `-`   `-----`  `-`   `-`  `-----`   `--`