Naftali  Kirsh, Svetitsky, Elisha , Burin, Alexander L, Schechter, Moshe , and Katz, Nadav . 2017. ?Revealing The Nonlinear Response Of A Tunneling Two-Level System Ensemble Using Coupled Modes?. Physical Review Materials, 1, Pp. 012601. doi:10.1103/PhysRevMaterials.1.012601.