Optical physics

  • Article
    | Open Access

    By placing an antiferromagnet next to a heavy metal such as platinum, magnetic excitations in the antiferromagnet drive a spin current in the heavy metal, leading to terahertz emission. Here, Kholid et al study the terahertz emission of two antiferromagnets, KCoF3 and KNiF3 with very different magnon frequencies, and find that the opening of a gap in the magnon density of states drastically alters the spin-transfer efficiency.

    • Farhan Nur Kholid
    • , Dominik Hamara
    •  & Chiara Ciccarelli
  • Article
    | Open Access

    Resonators are key components in optics. In this work, the authors introduce a class of optical resonators with distinctly different properties from conventional resonators, allowing fundamental design trade-offs to be circumvented.

    • Vincent Ginis
    • , Ileana-Cristina Benea-Chelmus
    •  & Federico Capasso
  • Article
    | Open Access

    The origin of the Rayleigh–Jeans distribution associated with light thermalization in optical thermodynamic multimode nonlinear settings is discussed. Here the authors show that due to entropy maximization, this process is universal and is independent of the intricacies of the nonlinearities involved.

    • Qi Zhong
    • , Fan O. Wu
    •  & Demetrios N. Christodoulides
  • Article
    | Open Access

    Quantum random number generators should ideally rely on few assumptions, have high enough generation rates, and be cost-effective and easy to operate. Here, the authors show an untrusted-homodyne-based MDI scheme that does not rely on i.i.d. assumption and is secure against quantum side information.

    • Chao Wang
    • , Ignatius William Primaatmaja
    •  & Charles Lim
  • Article
    | Open Access

    Flexible and coherent light generation is of paramount importance to enable new functionalities in integrated silicon photonics. Here the authors, develop an optical parametric oscillator with high conversion efficiency and high output power, based on the third order nonlinearity in a silicon nitride microresonator

    • Edgar F. Perez
    • , Grégory Moille
    •  & Kartik Srinivasan
  • Article
    | Open Access

    Studies on the fractional Schrödinger equation (FSE) remain mostly theoretical, due to the lack of materials supporting fractional dispersion or diffraction. Here, the authors indirectly realized the FSE using two programmable holograms acting as an optical Lévy waveguide.

    • Shilong Liu
    • , Yingwen Zhang
    •  & Ebrahim Karimi
  • Article
    | Open Access

    Frequency-bin qubits get the best of time-bin and dual-rail encodings, but require external modulators and pulse shapers to build arbitrary states. Here, instead, the authors work directly on-chip by controlling the interference of biphoton amplitudes generated in multiple, coherently-pumped ring resonators.

    • Marco Clementi
    • , Federico Andrea Sabattoli
    •  & Daniele Bajoni
  • Article
    | Open Access

    The authors investigate whether strong light-matter coupling can alter the nonlinear optical response of molecules inside a microcavity. Focusing on electroabsorption as a model third order nonlinearity, they find that apparent discrepancies between experiment and classical transfer matrix modeling arise from dark states in the system and are not a sign of new physics in the strong coupling regime.

    • Chiao-Yu Cheng
    • , Nina Krainova
    •  & Noel C. Giebink
  • Article
    | Open Access

    The authors present a single-shot 3D imaging approach utilizing carefully designed point clouds projection based on a metasurface device. They show submillimeter depth accuracy and demonstrate the potential for hand gesture detection.

    • Xiaoli Jing
    • , Ruizhe Zhao
    •  & Lingling Huang
  • Article
    | Open Access

    Physical or chemical reactions driven by light absorption are ruled by excited-state multidimensional energy surfaces displaced with respect to the ground state. Here the authors introduce a nonlinear Raman experiment to access an elusive aspect of the excited-state displacements: their sensed directions relative to the ground-state.

    • Giovanni Batignani
    • , Emanuele Mai
    •  & Tullio Scopigno
  • Article
    | Open Access

    There are many possible mechanisms of high-harmonic generation from crystals. Here the authors discuss the role of the Bloch oscillation to nonlinear response of the crystal and harmonic radiation from it.

    • Jan Reislöhner
    • , Doyeong Kim
    •  & Adrian N. Pfeiffer
  • Article
    | Open Access

    Here, the authors predict that plasmons in two-dimensional materials with closely located electron and hole Fermi pockets can be amplified when an electrical current bias is applied along the displaced electron-hole pockets, without the need for an external gain medium.

    • Sang Hyun Park
    • , Michael Sammon
    •  & Tony Low
  • Article
    | Open Access

    The parity-time symmetry has led to exotic phenomena and fruitful applications in optical systems. In this paper, the authors propose a leaky-wave-enabled anti-parity-time design and realize space-wave harnessing.

    • Yumeng Yang
    • , Xinrong Xie
    •  & Fei Gao
  • Article
    | Open Access

    The recently demonstrated approaches to fabrication of quantum emitters in silicon result in their random positioning, hindering applications in quantum photonic integrated circuits. Here the authors demonstrate controlled fabrication of telecom-wavelength quantum emitters in silicon wafers by focused ion beams.

    • Michael Hollenbach
    • , Nico Klingner
    •  & Georgy V. Astakhov
  • Article
    | Open Access

    ‘Giant atom’ physics occurs when the size of the atomic system becomes comparable to the wavelength of the light it interacts with. For atoms, such a regime is impossible to reach, however, for artificial atomic systems such ‘giant atom’ physics can be explored. Here, Wang et al demonstrate giant spin ensembles, consisting of magnetic spheres coupled to a microwave waveguide.

    • Zi-Qi Wang
    • , Yi-Pu Wang
    •  & J. Q. You
  • Article
    | Open Access

    The existing paradigms of system-bath control typically assume that the bath state is unchanged. By using spin defects in diamond, Dasari et al. demonstrate a scheme for controlling the state of the nuclear spin bath via selective measurements of the central qubit as a way of extending the qubit coherence time.

    • Durga Bhaktavatsala Rao Dasari
    • , Sen Yang
    •  & Jörg Wrachtrup
  • Article
    | Open Access

    Lead halide perovskites have recently emerged as a promising platform for the study of polariton superfluidity at room temperature. Here the authors report a complete set of quantum fluid phase transitions in both 1D and 2D homogeneous single crystals of CsPbBr3.

    • Kai Peng
    • , Renjie Tao
    •  & Wei Bao
  • Article
    | Open Access

    Spin simulators can solve many combinatorial optimization problems that can be represented by spin models, but they are limited to low-dimensional spins. Here the authors propose a simulator of multidimensional spins in arbitrary dimension, using a system of coupled parametric oscillators with a common pump.

    • Marcello Calvanese Strinati
    •  & Claudio Conti
  • Article
    | Open Access

    Here the authors report the development of a topological nonlinear parametric amplification in a dimerized, Su-Schrieffer-Heeger waveguide. Kerr-induced chiral symmetry breaking is demonstrated, showcasing how nonlinearities may control transitions of topological modes to bulk states.

    • Byoung-Uk Sohn
    • , Yue-Xin Huang
    •  & Dawn T. H. Tan
  • Article
    | Open Access

    The authors demonstrate on-the-fly reconfigurable optical trapping of organic polariton condensates which are delocalised over a macroscopic distance from the excitation region, holding great potential for future work on polaritonic lattice physics.

    • Mengjie Wei
    • , Wouter Verstraelen
    •  & Hamid Ohadi
  • Article
    | Open Access

    Floquet engineering aims at inducing new properties in materials with light. Here the authors have used pulses of variable durations, to investigate its applicability in the femtosecond domain. Surprisingly, they found that it holds to the few-cycle limit.

    • Matteo Lucchini
    • , Fabio Medeghini
    •  & Mauro Nisoli
  • Article
    | Open Access

    Here, the authors integrate a photonic crystal, supporting photonic bound states in the continuum (BICs), with monolayer WSe2, and leverage the high energy confinement of the BIC modes to demonstrate coherent directional dark exciton emission.

    • Xuezhi Ma
    • , Kaushik Kudtarkar
    •  & Shoufeng Lan
  • Article
    | Open Access

    Controlling the high-power laser transmittance is built on the diverse manipulation of multiple nonlinear absorption processes in the nonlinear optical materials. Here, the authors demonstrate the crucial role of hot-carrier effect to tune the nonlinear absorption response in quasi-2D perovskite films.

    • Gang Wang
    • , Tanghao Liu
    •  & Guichuan Xing
  • Article
    | Open Access

    Many recent studies have explored the response of magnetic systems to circularly polarised light. To achieve this, typically experiments use a birefringent crystal. Here, Yang et al show that any small error in the alignment of the crystal can result in a beam shift, and this shift can lead to spurious signals similar yet unrelated to the electron spin.

    • Haozhe Yang
    • , Eva Schmoranzerová
    •  & Ioan-Mihai Miron
  • Article
    | Open Access

    Extending the control over topological system will open the doors to both fundamental studies and applications. Here the authors demonstrate thouless topological transport of light in a bulk tunable moiré lattice.

    • Peng Wang
    • , Qidong Fu
    •  & Fangwei Ye
  • Article
    | Open Access

    A unified metric to assess the performances of quantum transducers, i.e., converters of quantum information between different physical systems - is still lacking. Here the authors propose quantum capacity as such metric, and use it to investigate the optimal designs of generic quantum transduction schemes.

    • Chiao-Hsuan Wang
    • , Fangxin Li
    •  & Liang Jiang
  • Article
    | Open Access

    Achieving optical cryptography scheme with both high capacity and security is highly desirable. Here, authors report a Stokes meta-hologram with a hierarchical encryption strategy that allows vector encryptions to produce depth-masked ciphertexts.

    • Xuyue Guo
    • , Peng Li
    •  & Jianlin Zhao
  • Article
    | Open Access

    The authors demonstrate a label-free superresolution imaging method by using a hyperbolic material as a substrate for tailored light-matter interactions. The hyperbolic material enhanced scattering, combined with dark-field detection, result in 5.5-fold resolution improvement beyond the diffraction limit.

    • Yeon Ui Lee
    • , Shilong Li
    •  & Zhaowei Liu
  • Article
    | Open Access

    Under strong laser fields, materials exhibit extreme non-linear optical response, such as high harmonic generation. These higher harmonics provide insights into electron behaviour in materials in sub-laser cycle timescale. Here, Cha et al study higher harmonic generation resulting from the laser driven motion of massless Dirac fermions in graphene.

    • Soonyoung Cha
    • , Minjeong Kim
    •  & Jonghwan Kim
  • Article
    | Open Access

    The optoelectronic performance of lead halide perovskite in highfluence applications are hindered by heterogeneous multi-polaron interactions in the nanoscale. Here, Nishda et al. spatially resolve sub-ns relaxation dynamics on the nanometer scale by ultrafast infrared pumpprobe nanoimaging.

    • Jun Nishida
    • , Peter T. S. Chang
    •  & Markus B. Raschke
  • Article
    | Open Access

    THz imaging and spectroscopy always request even more efficient components. Here the authors, thanks to a modified photoconductive switch that includes a graphene layer, demonstrate a high-speed photoconductive switch without sacrificing the generated power.

    • Dehui Zhang
    • , Zhen Xu
    •  & Zhaohui Zhong
  • Article
    | Open Access

    Deep understanding of defect physics, excitonic properties and the ultrafast carrier dynamics in the high mobility p-type transparent CuI is vital for its optoelectronic applications. Here, Liu et al. employ a synergistic approach to unveil these fundamental properties.

    • Zhan Hua Li
    • , Jia Xing He
    •  & Chao Ping Liu
  • Article
    | Open Access

    Dipolar excitons enable large nonlinear interaction but are usually hampered by their weak oscillator strength. Here, the authors demonstrate the strong light-matter coupling of interlayer dipolar excitons having unusually large oscillator strength in bilayer MoS2 resulting in highly nonlinear dipolar polaritons.

    • Biswajit Datta
    • , Mandeep Khatoniar
    •  & Vinod M. Menon
  • Article
    | Open Access

    We show frequency domain mirrors that provide reflections of optical mode propagation in the frequency domain. We theoretically investigated the mirror properties and experimentally demonstrate it using polarization and coupled-resonator-based coupling on thin film Lithium Niobate.

    • Yaowen Hu
    • , Mengjie Yu
    •  & Marko Lončar
  • Article
    | Open Access

    Here, the authors integrate measured fabrication constraints in topology optimization to design a highly optimized dielectric nanocavity. The theoretically predicted confinement of light below the diffraction limit is confirmed by near- and far-field spectroscopy.

    • Marcus Albrechtsen
    • , Babak Vosoughi Lahijani
    •  & Søren Stobbe
  • Article
    | Open Access

    Slow light effects are interesting for telecommunications and quantum photonics applications. Here, the authors use coupled exciton-surface plasmon polaritons (SPPs) in a hybrid monolayer WSe2-metallic waveguide structure to demonstrate a 1300-fold reduction of the SPP group velocity.

    • Matthew Klein
    • , Rolf Binder
    •  & John R. Schaibley
  • Article
    | Open Access

    The use of machine learning to characterise quantum states has been demonstrated, but usually training the algorithm using data from the same state one wants to characterise. Here, the authors show an algorithm that can learn all states that share structural similarities with the ones used for the training.

    • Yan Zhu
    • , Ya-Dong Wu
    •  & Giulio Chiribella
  • Article
    | Open Access

    Experimental studies of the Casimir effect have involved only interactions between two bodies so far. Here, the authors observe a micrometer-thick cantilever under the Casimir force exerted by microspheres from two sides simultaneously.

    • Zhujing Xu
    • , Peng Ju
    •  & Tongcang Li
  • Article
    | Open Access

    Fibre-based entanglement distribution represents a key primitive for quantum applications such as QKD. Here, the authors demonstrate it across 248 km of deployed fiber, observing stable detected pair rates of 9 Hz for 110 h.

    • Sebastian Philipp Neumann
    • , Alexander Buchner
    •  & Rupert Ursin
  • Article
    | Open Access

    Successfully controlling an optical signal by a single gate photon would have great applicability for quantum networks and all-optical computing. Here, the authors realise a single-photon transistor in the microwave regime based on superconducting quantum circuits.

    • Zhiling Wang
    • , Zenghui Bao
    •  & Luming Duan