Achieving effcient,high-power harmonic generation in the terahertz spectral domain has technological applications,for example,in sixth generation(6G)communication networks.Massless Dirac fermions possess extremely lar...Achieving effcient,high-power harmonic generation in the terahertz spectral domain has technological applications,for example,in sixth generation(6G)communication networks.Massless Dirac fermions possess extremely large terahertz nonlinear susceptibilities and harmonic conversion effciencies.However,the observed maximum generated harmonic power is limited,because of saturation effects at increasing incident powers,as shown recently for graphene.Here,we demonstrate room-temperature terahertz harmonic generation in a Bi_(2)Se_(3) topological insulator and topological-insulator-grating metamaterial structures with surface-selective terahertz field enhancement.We obtain a third-harmonic power approaching the miliwatt range for an incident power of 75 mW-an improvement by two orders of magnitude compared to a benchmarked graphene sample.We establish a framework in which this exceptional performance is the result of thermodynamic harmonic generation by the massless topological surface states,benefiting from ultrafast dissipation of electronic heat via surface-bulk Coulomb interactions.These results are an important step towards on-chip terahertz(opto)electronic applications.展开更多
基金G.Kh.Kitaeva and K.A.Kuznetsov.KJ.T.acknowledges funding from the European Union's Horizon 2020 research and innovation program under Grant Agreement No.804349(ERC StG CUHL),RYC fellowship No.RYC-2017-22330,and IAE project PID2019-111673GB-100ICN2 was supported by the Severo Ochoa program from Spanish MINECO Grant No.SEV-2017-0706+3 种基金A.P.acknowledges support from the European Commission under the EU Horizon 2020 MSCA-RISE-2019 programme(project 873028 HYDROTRONICS)and from the Leverhulme Trust under the grant RPG-2019-363S.S..K.B.T.K,and L.W.M.acknowledge support by the SFB1170(DFG project ID 258499086)C.G.and S.0.V.acknowledge support from the European Union's Horizon 2020 FET-PROACTIVE project TOCHA under grant agreement 824140T.K,L.W.M,and G.V.A.acknowledge the financial support from the Wurzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter(EXC 2147,390858490).
文摘Achieving effcient,high-power harmonic generation in the terahertz spectral domain has technological applications,for example,in sixth generation(6G)communication networks.Massless Dirac fermions possess extremely large terahertz nonlinear susceptibilities and harmonic conversion effciencies.However,the observed maximum generated harmonic power is limited,because of saturation effects at increasing incident powers,as shown recently for graphene.Here,we demonstrate room-temperature terahertz harmonic generation in a Bi_(2)Se_(3) topological insulator and topological-insulator-grating metamaterial structures with surface-selective terahertz field enhancement.We obtain a third-harmonic power approaching the miliwatt range for an incident power of 75 mW-an improvement by two orders of magnitude compared to a benchmarked graphene sample.We establish a framework in which this exceptional performance is the result of thermodynamic harmonic generation by the massless topological surface states,benefiting from ultrafast dissipation of electronic heat via surface-bulk Coulomb interactions.These results are an important step towards on-chip terahertz(opto)electronic applications.
