  The design of a self-complementary metallic checkerboard pattern achieves
broadband, dispersion-less, and maximized absorption, concentrating in the deep
subwavelength resistive connections between squares, without any theoretical
limitation on the energy absorbing area. Here, we experimentally and
numerically investigate the electromagnetic response in the limit of extremely
small connections. We show that finite conductivity and randomness in a
near-self-complementary checkerboard pattern plays a crucial role in producing
a frequency-independent energy loss in the terahertz frequency region. Here
metals behave like an almost perfect conductor. When the checkerboard pattern
approaches the perfect self-complementary pattern, the perfect conductor
approximation spontaneously breaks down, owing to the finite conductivity at
the nano- scale connection, leading to broadband absorption. It is also shown
that the random connections between metallic squares also lead to broadband and
maximized energy loss through scattering loss, similar to finite conductivity.
