## Experimental observation of the dual behavior of PT-symmetric scattering

Zin Lin, Joseph Schindler, Fred M. Ellis, Tsampikos Kottos

We investigate experimentally parity-time $${\cal PT}$$ symmetric scattering using $$LRC$$ circuits in an inductively coupled $${\cal PT}$$- symmetric pair connected to transmission line leads. In the single-lead case, the $${\cal PT}$$-symmetric circuit acts as a simple dual device – an amplifier or an absorber depending on the orientation of the lead. When a second lead is attached, the system exhibits unidirectional transparency for some characteristic frequencies. This non-reciprocal behavior is a consequence of generalized (non-unitary) conservation relations satisfied by the scattering matrix.

http://arxiv.org/abs/1205.2176
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)