“…More recently there have been papers where, contact potentials have been used to study the effects of resonant tunneling [24,25], to study their properties under the effect of external fields [26], and their applications in the study of metamaterials [27]. In addition the effects of several contact potential barriers have been studied in [28,29,30,31,32,33] and extensions to arbitrary dimension have been considered in [34] generalising the approach by Jackiw in [15]. Mathematical properties of potentials decorated with contact interactions have also been the object of recent studies [35,36,37,38,39,40,41].…”