Topological Defect Engineering and PT Symmetry in Non-Hermitian Electrical Circuits.

  title={Topological Defect Engineering and PT Symmetry in Non-Hermitian Electrical Circuits.},
  author={Alexander Stegmaier and Stefan Imhof and Tobias Helbig and Tobias Hofmann and Ching Hua Lee and Mark Kremer and Alexander Fritzsche and Thorsten Feichtner and Sebastian Klembt and S. Hofling and Igor Boettcher and Ion Cosma Fulga and Oliver G. Schmidt and Martin Greiter and Tobias Kie{\ss}ling and Alexander Szameit and Ronny Thomale},
  journal={Physical review letters},
  volume={126 21},
We employ electric circuit networks to study topological states of matter in non-Hermitian systems enriched by parity-time symmetry PT and chiral symmetry anti-PT (APT). The topological structure manifests itself in the complex admittance bands which yields excellent measurability and signal to noise ratio. We analyze the impact of PT-symmetric gain and loss on localized edge and defect states in a non-Hermitian Su-Schrieffer-Heeger (SSH) circuit. We realize all three symmetry phases of the… 

Figures from this paper

Edge state mimicking topological behavior in a one-dimensional electrical circuit

For one-dimensional (1D) topological insulators, the edge states always reside in the bulk bandgaps as isolated modes. The emergence and vanishing of these topological edge states are always

Unveiling Topological Charges and Their Manipulation in Electronic Circuits

Leveraging topological properties in the response of electromagnetic systems can greatly enhance their potential. Although the investigation of singularity-based electromagnetics and non-Hermitian

Non-Hermitian Pseudo-Gaps

Inner Skin Effects on Non-Hermitian Topological Fractals

Non-Hermitian (NH) crystals, quasicrystals and amorphous network with only open boundary condition feature skin effect, displaying accumulation of a macroscopic number of states near one of its

Multiple crossed non-Hermitian Su-Schrieffer-Heeger chains coupled via a mutual defect site

We analyze topological systems with dimensions larger than one, comprised of several one-dimensional Su-SchriefferHeeger (SSH) lattices coupled through a single defect. The defect induces edges

Room-Temperature Topological Polariton Laser in an Organic Lattice.

This communication demonstrates exciton-polariton lasing for topological defects emerging from the imprinted lattice structure at room temperature, using red fluorescent protein derived from DsRed of Discosoma sea anemones and a patterned mirror cavity to tune the lattice potential landscape of a linear Su-Schrieffer-Heeger chain.

Non-Hermitian Squeezed Polarons

Recent experimental breakthroughs in non-Hermitian ultracold atomic lattices have dangled tantalizing prospects in realizing exotic, hitherto unreported many-body non-Hermitian quantum phenomena. In

Linear response for pseudo-Hermitian Hamiltonian systems: Application to PT -symmetric qubits

Motivated by the recent advances in modelling the pseudo-Hermitian Hamiltonian (pHH) systems using superconducting qubits we analyze their quantum dynamics subject to a small time-dependent



Observation of an anti-PT-symmetric exceptional point and energy-difference conserving dynamics in electrical circuit resonators

An electrical circuit producing key non-Hermitian properties and unusual wave dynamics grounded on anti-PT (APT) symmetry is experimentally demonstrated and unique properties of APT-symmetric systems are experimentally confirmed.

Topologically protected bound states in photonic parity-time-symmetric crystals.

This work shows theoretically and experimentally the existence of states that are localized at the interface between two topologically distinct PT-symmetric photonic lattices, and finds analytical closed form solutions of topological PT-Symmetric interface states.

Selective enhancement of topologically induced interface states in a dielectric resonator chain

A topologically induced defect state is realized in a chain of dielectric microwave resonators and it is shown that the functionality of the system can be enhanced by supplementing topological protection with non-hermitian symmetries that do not have an electronic counterpart.

Topolectrical-circuit realization of topological corner modes

Quantized electric quadrupole insulators have recently been proposed as novel quantum states of matter in two spatial dimensions. Gapped otherwise, they can feature zero-dimensional topological

A quantized microwave quadrupole insulator with topologically protected corner states

This work demonstrates experimentally a member of this predicted class of materials—a quantized quadrupole topological insulator—produced using a gigahertz-frequency reconfigurable microwave circuit, and provides conclusive evidence of a unique form of robustness against disorder and deformation, which is characteristic of higher-order topologicalinsulators.

Circuit implementation of a four-dimensional topological insulator

Here, Wang et al. realise a four-dimensional topological insulator associated with a nonzero second Chern number using electric circuits, which paves the way to the use of electric circuits for exploring high-dimensionalTopological models.

Topological edge states of interacting photon pairs emulated in a topolectrical circuit

A classical structure based on topolectrical circuits is designed which serves as a simulator of a quantum-optical one-dimensional system featuring the topological state of two photons induced by the effective photon-photon interaction, emulating two-Photon topological bound states in 1D using a 2D electrical circuit.

Generalized bulk–boundary correspondence in non-Hermitian topolectrical circuits

The study of the laws of nature has traditionally been pursued in the limit of isolated systems, where energy is conserved. This is not always a valid approximation, however, as the inclusion of

Self-induced topological protection in nonlinear circuit arrays

The interplay between topology and many-body physics has been a topic of strong interest in condensed matter physics for several years. For electronic systems, research has so far focused on linear

Impurity induced scale-free localization

Non-Hermitian systems have been shown to have a dramatic sensitivity to their boundary conditions. In particular, the non-Hermitian skin effect induces collective boundary localization upon turning