PT-Symmetric Electronics

TL;DR

This paper demonstrates both theoretically and experimentally that PT-symmetric electronic circuits exhibit unique behaviors such as simultaneous amplification and absorption, providing new insights into non-Hermitian physics.

Contribution

It introduces a practical PT-symmetric electronic system with a Liouvillian formulation, enabling detailed analysis of its scattering and mode properties.

Findings

The PT-dimer exhibits typical PT-symmetric mode behavior.

Scattering signals reveal PT-symmetry effects.

Device can act as an amplifier or absorber depending on wave direction.

Abstract

We show both theoretically and experimentally that a pair of inductively coupled active LRC circuits (dimer), one with amplification and another with an equivalent amount of attenuation, display all the features which characterize a wide class of non-Hermitian systems which commute with the joint parity-time PT operator: typical normal modes, temporal evolution, and scattering processes. Utilizing a Liouvilian formulation, we can define an underlying PT-symmetric Hamiltonian, which provides important insight for understanding the behavior of the system. When the PT-dimer is coupled to transmission lines, the resulting scattering signal reveals novel features which reflect the PT-symmetry of the scattering target. Specifically we show that the device can show two different behaviors simultaneously, an amplifier or an absorber, depending on the direction and phase relation of the interrogating waves. Having an exact theory, and due to its relative experimental simplicity, PT-symmetric electronics offers new insights into the properties of PT-symmetric systems which are at the forefront of the research in mathematical physics and related fields.