Electromagnetically-induced-transparency-like phenomenon with resonant meta-atoms in a cavity

We experimentally investigate a cavity in which two resonant meta-atoms are embedded. Its corresponding response spectrum to an incident microwave shows an electromagnetically-induced-transparency-like (EIT-like) phenomenon when the meta-atoms are arranged in the sequence node-antinode but not in the sequence antinode-node. We carry out in situ measurements of the cavity field to bring physical insight into this asymmetric response, and use the transfer matrix method joined with coupled-mode theory to give a quantitative analysis. Finally, we demonstrate the unidirectional EIT-like behavior in a two-port design. Our results may benefit novel nonreciprocal devices in the future by exploring the nonlinearity of the meta-atoms with this asymmetric arrangement.