The genome sequence of star fruit(Averrhoa carambola)

Oxalidaceae is one of the most important plant families in horticulture,and its key commercially relevant genus,Averrhoa,has diverse growth habits and fruit types.Here,we describe the assembly of a high-quality chromosomescale genome sequence for Averrhoa carambola(star fruit).Ks distribution analysis showed that A.carambola underwent a whole-genome triplication event,i.e.,the gamma event shared by most eudicots.Comparisons between A.carambola and other angiosperms also permitted the generation of Oxalidaceae gene annotations.We identified unique gene families and analyzed gene family expansion and contraction.This analysis revealed significant changes in MADS-box gene family content,which might be related to the cauliflory of A.carambola.In addition,we identified and analyzed a total of 204 nucleotide-binding site,leucine-rich repeat receptor(NLR)genes and 58 WRKY genes in the genome,which may be related to the defense response.Our results provide insights into the origin,evolution and diversification of star fruit.

Single photon emitter deterministically coupled to a topological corner state

Incorporating topological physics into the realm of quantum photonics holds the promise of developing quantum light emitters with inherent topological robustness and immunity to backscattering.Nonetheless,the deterministic interaction of quantum emitters with topologically nontrivial resonances remains largely unexplored.Here we present a single photon emitter that utilizes a single semiconductor quantum dot,deterministically coupled to a second-order topological corner state in a photonic crystal cavity.By investigating the Purcell enhancement of both single photon count and emission rate within this topological cavity,we achieve an experimental Purcell factor of Fp=3.7.Furthermore,we demonstrate the on-demand emission of polarized single photons,with a second-order autocorrelation function g(2)(0)as low as 0.024±0.103.Our approach facilitates the customization of light-matter interactions in topologically nontrivial environments,thereby offering promising applications in the field of quantum photonics.

High-speed electro-optic modulation in topological interface states of a one-dimensional lattice

lectro-optic modulators are key components in data communication,microwave photonics,and quantum photonics.Modulation bandwidth,energy efficiency,and device dimension are crucial metrics of modulators.Here,we provide an important direction for the miniaturization of electro-optic modulators by reporting on ultracompact topological modulators.A topological interface state in a one-dimensional lattice is implemented on a thin-film lithium-niobate integrated platform.Due to the strong optical confinement of the interface state and the peaking enhancement of the electro-optic response,a topological cavity with a size of 1.6×140μm^(2)enables a large modulation bandwidth of 104 GHz.The first topological modulator exhibits the most compact device size compared to reported LN modulators with bandwidths above 28 GHz,to the best of our knowledge.100 Gb/s non-return-to-zero and 100 Gb/s four-level pulse amplitude modulation signals are generated.The switching energy is 5.4 fJ/bit,owing to the small electro-optic mode volume and low capacitance.The topological modulator accelerates the response time of topological photonic devices from the microsecond order to the picosecond order and provides an essential foundation for the implementation of large-scale lithium-niobate photonic integrated circuits.

Ultracompact topological photonic switch based on valley-vortex-enhanced high-efficiency phases shift

Topologically protected edge states based on valley photonic crystals(VPCs)have been widely studied,from theoretical verifcation to technical applications.However,research on integrated tuneable topological devices is still lacking.Here,we study the phase-shifting theory of topological edge modes based on a VPC structure.Benefiting from the phase vortex formed by the VPC structure,the optical path of the topological edge mode in the propagation direction is approximately two-fold that of the conventional optical mode in a strip waveguide.In experiments,we show a 1.57-fold improvement inπ-phase tuning efficiency.By leveraging the highefficiency phase-shifting properties and the sharp-turn features of the topological waveguide,we demonstrate an ultracompact 1×2 thermo-optic topological switch(TOTS)operating at telecommunication wavelengths.A switching power of 18.2 mW is needed with an ultracompact device footprint of 25.66×28.3μm in the wavelength range of 1530-1582 nm.To the best of our knowledge,this topological photonic switch is the smallest switch of any dielectric or semiconductor 1×2/2×2 broadband optical switches,including thermo-optic and electro-optic switches.In addition,a high-speed transmission experiment employing the proposed TOTS is carried out to demonstrate the robust transmission of high-speed data.Our work reveals the phase shifting mechanism of valley edge modes,which may enable diverse topological functional devices in many fields,such as optical communications,nanophotonics,and quantum information processing.