  Thanks to the pioneering studies conducted on the fields of transformation
optics (TO) and metasurfaces, many unprecedented devices such as invisibility
cloaks have been recently realized. However, each of these methods has some
drawbacks limiting the applicability of the designed devices for real-life
scenarios. For instance, TO studies lead to bulky coating layer with the
thickness that is comparable to, or even larger than the dimension of the
concealed object. In this paper, based on the coordinate transformation, an
ultrathin carpet cloak is proposed to hide objects with arbitrary shape and
size using a thin anisotropic material, called as infinitely anisotropic medium
(IAM). It is shown that unlike the previous metasurface-based carpet cloaks,
the proposed IAM hides objects from all viewing incident angles while it is
extremely thin compared with the object dimensions. This material also
circumvents the conventional transformation optics complexities and could be
easily implemented in practical scenarios. To demonstrate the capability of the
proposed carpet cloak, several full-wave simulations are carried out. Finally,
as a proof of concept, the IAM is implemented based on the effective medium
theory which exhibits good agreement with the results obtained from the
theoretical investigations. The introduced material not only constitutes a
significant step towards the invisibility cloak but also can greatly promote
the practical application of the other TO-based devices.
