Gain and loss induced topological insulating phase in a non Hermitian electrical circuit

Abstract

There have been considerable efforts devoted to the study of topological phases in certain non-Hermitian systems that possess real eigenfrequencies in the presence of gain and loss. However, it is challenging to experimentally realize such non-Hermitian topological insulators in either quantum or photonic systems, due to the difficulties in introducing controlled gain and loss. On the other hand, the wide choices of active circuit components provide us with unprecedented convenience and flexibility in engineering non-Hermitian topological insulators in electrical circuits. Here, we report experimental realization of a one-dimensional (1D) non-Hermitian topological circuit which exhibits topologically protected edge state purely induced by gain and loss. We show that by tuning the value of the positive/negative resistors in the circuit, our system can switch between different topological phase regions. The topological edge states and interface states are observed at the circuit edge and at the interface between a trivial and nontrivial circuit, which are manifested by a prominent impedance peak at the mid-gap frequency topologically robust to variations of circuit parameters. Our work opens a new gateway towards actively controllable topological systems.

References in corpus (23)

• Real Spectra in Non-Hermitian Hamiltonians Having PT Symmetry
• Topological insulators and superconductors: ten-fold way and dimensional hierarchy
• Topological Acoustics
• Topolectrical circuit realization of topological corner modes
• Topolectrical circuits
• Selective enhancement of topologically induced interface states in a dielectric resonator chain
• Edge states and topological phases in non-Hermitian systems
• Time Reversal Invariant Topologically Insulating Circuits
• Topological properties of linear circuit lattices
• Classification of topological phonons in linear mechanical metamaterials
• Photonic Topological Insulating Phase Induced Solely by Gain and Loss
• Topological Phases of Sound and Light
• PT-Symmetry in Non-Hermitian Su-Schrieffer-Heeger model with complex boundary potentials
• Topological invariance and global Berry phase in non-Hermitian systems
• Higher-order topological electric circuits and topological corner resonance on the breathing Kagome and pyrochlore lattices
• Probing the Berry Curvature and Fermi Arcs of a Weyl Circuit
• Topological quantum wires with balanced gain and loss
• Topological nodal states in circuit lattice
• Topological circuits of inductors and capacitors
• Time-Reversal Symmetry in Non-Hermitian Systems
• Topological Zak Phase in Strongly-Coupled LC Circuits
• Nodal Manifolds Bounded by Exceptional Points on Non-Hermitian Honeycomb Lattices and Electrical-Circuit Realizations
• Comment on "Anomalous Edge State in a Non-Hermitian Lattice"

Cited by in corpus (50)

• Non-Hermitian Dirac Cones
• Topolectric circuits: Theory and construction
• Topological insulators and semimetals in classical magnetic systems
• Topological metasurface: From passive toward active and beyond
• Dimensional transmutation from non-Hermiticity
• Dimerization induced mobility edges and multiple reentrant localization transitions in non-Hermitian quasicrystals
• Non-Hermitian waves in a continuous periodic model and application to photonic crystals
• Dissipative Floquet Dynamical Quantum Phase Transition
• Non-Hermitian Chiral Skin Effect
• Universal competitive spectral scaling from the critical non-Hermitian skin effect
• Non-Hermitian topological phases and dynamical quantum phase transitions: A generic connection
• Experimental observation of non-Hermitian higher-order skin interface states in topological electric circuits
• Demonstration of acoustic high-order Stiefel-Whitney semimetal in bilayer graphene sonic crystals
• Non-Hermitian Squeezed Polarons
• Hybrid higher-order skin-topological effect in hyperbolic lattices
• Experimental realization of two-dimensional weak topological insulators
• Emergent $\mathcal{P}\mathcal{T}$ symmetry in a double-quantum-dot circuit QED set-up
• Hinge solitons in three-dimensional second-order topological insulators
• Generalized bulk-boundary correspondence in periodically driven non-Hermitian systems
• Percolation-induced PT symmetry breaking
• Observation of a topological edge state stabilized by dissipation
• Topological delocalization transitions and mobility edges in the nonreciprocal Maryland model
• Emergent non-Hermitian models
• Non-linear dynamics of the non-Hermitian Su-Schrieffer-Heeger model
• Non-Hermitian Floquet phases with even-integer topological invariants in a periodically quenched two-leg ladder
• Modified Generalized-Brillouin-Zone Theory with On-site Disorders
• Non-Hermitian spectral flows and Berry-Chern monopoles
• Non-Hermitian topology and criticality in photonic arrays with engineered losses
• Competition of non-Hermitian skin effect and topological localization of corner states observed in circuits
• Filling up complex spectral regions through non-Hermitian disordered chains
• Non-Hermitian second-order topological superconductors
• Observation of type-III corner states induced by long-range interactions
• The simulation of non-Hermitian disordered system in linear circuits
• Emerging exceptional point with breakdown of skin effect in non-Hermitian systems
• Electric circuit emulation of topological transitions driven by quantum statistics
• Unravelling the edge spectra of non-Hermitian Chern insulators
• Observation of non-local impedance response in a passive electrical circuit
• Correlation-induced phase transitions and mobility edges in an interacting non-Hermitian quasicrystal
• Non-Hermitian Haldane-Hubbard model: Effective description of one- and two-body dissipation
• Switchable Non-Hermitian Skin Effect in Bogoliubov Modes
• Mode-Shell correspondence, a unifying phase space theory in topological physics -- Part I: Chiral number of zero-modes
• Fate of pseudo mobility-edge and multiple states in non-Hermitian Wannier-Stark lattice
• Recognizing critical lines via entanglement in non-Hermitian systems
• Observation of dislocation-induced topological modes in a three-dimensional acoustic topological insulator
• Non-Hermitian Topoelectrical Circuits: Expedient Tools for Topological State Engineering with Gain-Loss Modulation
• Short-time behavior of a system ruled by non-Hermitian time-dependent Hamiltonians
• Diffusive Topological Transport in Spatiotemporal Thermal Lattices
• Interplay of Disorder and Point-Gap Topology: Chiral Modes, Localization and Non-Hermitian Anderson Skin Effect in One Dimension
• Anomalous Non-Hermitian Topological Anderson Insulator
• One-dimensional topology and topolectrics of nonsymmorphic Kramers degenerate systems