Article
Multidisciplinary Sciences
Ruotian Chen, Zefeng Ren, Yu Liang, Guanhua Zhang, Thomas Dittrich, Runze Liu, Yang Liu, Yue Zhao, Shan Pang, Hongyu An, Chenwei Ni, Panwang Zhou, Keli Han, Fengtao Fan, Can Li
Summary: The water-splitting reaction using photocatalyst particles is a promising route for solar fuel production. In this study, researchers performed spatiotemporally resolved surface photovoltage measurements on cuprous oxide photocatalyst particles and found that photogenerated electrons are transferred to the catalytic surface quickly through inter-facet hot electron transfer, while photogenerated holes are transferred to a spatially separated surface and stabilized through selective trapping. These findings contribute to the efficient charge separation in photocatalysis and have implications for the rational design of photocatalysts.
Article
Physics, Multidisciplinary
Sebastian Pres, Bernhard Huber, Matthias Hensen, Daniel Fersch, Enno Schatz, Daniel Friedrich, Victor Lisinetskii, Ruben Pompe, Bert Hecht, Walter Pfeiffer, Tobias Brixner
Summary: In this study, the local detection of nanoscale plasmon quantum wave packets was achieved using plasmon-assisted electron emission as a signal in coherent two-dimensional nanoscopy. The existence of a plasmon quantum wave packet was demonstrated, and an improved model for plasmon-assisted electron emission processes was provided.
Article
Materials Science, Multidisciplinary
Y. -M. Robin Hu, Elena A. Ostrovskaya, Eliezer Estrecho
Summary: We theoretically investigate the dynamics of wave packets in a non-Hermitian, optically anisotropic exciton-polariton system and observe their self-acceleration and reshaping governed by their eigenenergies. The exciton-polariton wave packets tend to evolve into states with smaller decay rates, resulting in directional transport in real space. Pseudospin topological defects are also found on the imaginary Fermi arc. These dynamics can be observed experimentally in microcavities and other two-dimensional systems.
Article
Nanoscience & Nanotechnology
Naoki Ichiji, Yuka Otake, Atsushi Kubo
Summary: The spatiotemporal dynamics of a surface plasmon polariton wave packet interacting with a plasmonic nanocavity on a metal surface are studied. It is found that only the spectral component matching a specific energy level can continue propagating on the metal surface, leading to a spatial peak shift in the wave packet.
Article
Multidisciplinary Sciences
Ding Xu, Arkajit Mandal, James M. Baxter, Shan-Wen Cheng, Inki Lee, Haowen Su, Song Liu, David R. Reichman, Milan Delor
Summary: Semiconductor excitations can form exciton-polaritons with light-like energy flow and matter-like interactions. By using nonlinear momentum-resolved optical approach, the authors directly image the exciton-polaritons in real space on femtosecond scales. It is found that exciton-phonon interactions result in a renormalization of exciton-polariton velocities, but ballistic transport can be maintained for half-exciton polaritons. Upon increasing the excitonic character, rapid decoherence leads to diffusive transport.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Peter Vancso, Alexandre Mayer, Peter Nemes-Incze, Geza Istvan Mark
Summary: The paper introduces two calculation methods based on wave packet dynamics for studying the physical properties of materials under the influence of structural defects. By experimental verification, these methods can be used to study quasiparticle scattering and interference effects on 2D materials.
APPLIED SCIENCES-BASEL
(2021)
Article
Physics, Applied
Siyuan Huang, Peng Xu, Dingguo Zheng, Jun Li, Huanfang Tian, Huaixin Yang, Jianqi Li
Summary: Photon-induced near-field electron microscopy (PINEM) allows for near-field imaging with nanometer spatial resolution and femtosecond temporal resolution. We studied an asymmetric copper bowtie nanostructure and analyzed its plasmonic near-field distribution and lifetime. PINEM images revealed surface plasmon polaritons and local surface-plasmon resonance excitations with different polarizations. The distribution and intensity variations of the near-field were analyzed using finite-element simulations. This study provides important insights for the manipulation of plasmonic near-field and the design of plasmonic devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Ming Zhang, Zhengning Guo, Xiaoyu Mi, Zheng Li, Yunquan Liu
Summary: This article provides an overview of various imaging methods for molecular dynamics, including high-order harmonic generation imaging, photoelectron diffraction imaging, Coulomb explosion imaging, and diffraction imaging. These methods can be used to analyze laser-induced nuclear and electronic dynamics.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Physics, Multidisciplinary
Rhonald Burgos Atencia, Qian Niu, Dimitrie Culcer
Summary: This paper provides a general prescription for reformulating the semiclassical equations of motion for carriers in disordered conductors by using the quantum mechanical density matrix. The approach allows for averaging over impurity configurations and includes corrections to the semiclassical velocity and the expectation value of the spin operator. The prescription ensures that all vertex corrections present in diagrammatic treatments are taken into account.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Multidisciplinary Sciences
Takahiro Shimojima, Asuka Nakamura, Xiuzhen Yu, Kosuke Karube, Yasujiro Taguchi, Yoshinori Tokura, Kyoko Ishizaka
Summary: The study successfully tracked the dynamics of skyrmions and revealed their evolution at different time scales. The repeatable motion of magnetic skyrmions around defects demonstrates the arrangement and relaxation of skyrmion clusters.
Article
Materials Science, Multidisciplinary
Qiang Zhang, Zhirong Liu, Xun Wang
Summary: This paper introduces a new type of multi-dimensional spatiotemporal light field and proposes a method to generate it. The research shows that the generated wave packet exhibits non-diffraction and self-focusing properties during propagation, and the structure of the optical vortex is well preserved.
RESULTS IN PHYSICS
(2022)
Article
Physics, Multidisciplinary
A. Plunkett, M. A. Alarcon, J. K. Wood, C. H. Greene, A. Sandhu
Summary: Photoelectron interferometry with femtosecond and attosecond light pulses provides high temporal and spectral resolution. By stimulating Raman interferences and monitoring the modification of electron yield, we resolved the electronic composition and time evolution of autoionizing states in argon, with remarkable agreement between experimental and theoretical results.
PHYSICAL REVIEW LETTERS
(2022)
Review
Chemistry, Multidisciplinary
Gareth W. Richings, Scott Habershon
Summary: This article discusses the application of direct quantum dynamics methods in molecular photochemistry. By combining machine learning of potential energy surfaces (PESs) and nonadiabatic couplings with accurate quantum propagation schemes like the multiconfiguration time-dependent Hartree (MCTDH) method, a new generation of direct quantum dynamics tools has been developed that enables accurate on-the-fly simulations of molecular photochemistry. These simulations offer an alternative route to studying excited-state chemistry, such as photodissociation, proton and electron transfer, and ultrafast energy dissipation in complex molecular systems.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Optics
Jian Chen, Pengkun Zheng, Qiwen Zhan
Summary: This paper proposes cylindrical vector two-dimensional spatiotemporal optical vortices (2D-STOVs) and investigates their tightly focusing. The method presented enables the experimental generation of controllable optical toroidal wavepackets, with potential applications in various fields.
Article
Physics, Condensed Matter
Y. El-Helou, K-T Wu, A. Bruyant, W-Y Woon, M. Kazan
Summary: This study experimentally investigates the transition from surface phonon-polariton to surface phonon-plasmon-polariton by thermal injection of free carriers. The results demonstrate that injecting free carriers can tune the characteristics of surface phonon-polariton, leading to a shorter mean free path.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Chemistry, Physical
Yang Ge, Lingxiu Chen, Chengxin Jiang, Jianlong Ji, Qiuyun Tan, Douxing Pan, Wendong Zhang, Riguang Zhang, Eli Janzen, James H. Edgar, Shengbo Sang, Haomin Wang
Summary: In this study, triangular zigzag-edged graphene nanoflakes (GNFs) were successfully synthesized and found to exhibit high magnetization. Density functional theory calculations revealed that this magnetic property is a result of superexchange interactions among unpaired electrons at the zigzag C-BN interface. This research provides a promising platform for experimentally achieving GNFs with high electron spin states.
Article
Chemistry, Multidisciplinary
Hanan Herzig Sheinfux, Minwoo Jung, Lorenzo Orsini, Matteo Ceccanti, Aditya Mahalanabish, Daniel Martinez-Cercos, Iacopo Torre, David Barcons Ruiz, Eli Janzen, James H. Edgar, Valerio Pruneri, Gennady Shvets, Frank H. L. Koppens
Summary: This study successfully created nanoscale hypercrystals, and measured the Bloch modes of these crystals directly using scattering near-field microscopy. The dispersion of the Bloch modes was extracted and revealed a clear switch from positive to negative group velocity. The study also observed spectral features specific to hypercrystals, providing important insights into nanoscale light-matter interactions and the manipulation of optical density.
Article
Chemistry, Multidisciplinary
Ivan Madan, Eduardo J. C. Dias, Simone Gargiulo, Francesco Barantani, Michael Yannai, Gabriele Berruto, Thomas LaGrange, Luca Piazza, Tom T. A. Lummen, Raphael Dahan, Ido Kaminer, Giovanni Maria Vanacore, F. Javier Garcia de Abajo, Fabrizio Carbone
Summary: Understanding and actively controlling the dynamics of nonequilibrium electron clouds is crucial for various applications. However, these clouds evolve in a complex manner on small scales, making them difficult to study. In this study, we use an ultrafast transmission electron microscope to solve the challenge of characterizing the evolution of electron clouds generated on metallic structures, providing insights into their intricate mechanisms and dynamics. This technique, known as charge dynamics electron microscopy (CDEM), opens up possibilities for studying a wide range of nonequilibrium electrodynamic phenomena on the nanoscale.
Article
Chemistry, Multidisciplinary
Alexey Y. Nikitin, Rainer Hillenbrand, Andrei Bylinkin, Francesco Calavalle, Maria Barra-Burillo, Roman V. Kirtaev, Elizaveta Nikulina, Evgeny Modin, Eli Janzen, James H. Edgar, Felix Casanova, Luis E. Hueso, Valentyn S. Volkov, Paolo Vavassori, Igor Aharonovich, Pablo Alonso-Gonzalez
Summary: Strong coupling between light and matter excitations in both mid-IR and visible frequency bands is achieved by introducing polaritonic nanoresonators, which can manipulate material properties and have potential applications in optoelectronics, nanophotonics, and quantum information.
Article
Multidisciplinary Sciences
A. J. Sternbach, S. L. Moore, A. Rikhter, S. Zhang, R. Jing, Y. Shao, B. S. Y. Kim, S. Xu, S. Liu, J. H. Edgar, A. Rubio, C. Dean, J. Hone, M. M. Fogler, D. N. Basov
Summary: We visualized negative refraction of phonon polaritons, which occur when passing through a planar interface between molybdenum oxide (MoO3) and isotopically pure hexagonal boron nitride (h11BN). The polaritons, hybrids of infrared photons and lattice vibrations, form collimated rays that exhibit negative refraction. These rays can circulate along closed diamond-shaped trajectories at a specific frequency co0. We found that the polariton eigenmodes display regions of both positive and negative dispersion, with multiple gaps resulting from polaritonic-level repulsion and strong coupling.
Article
Optics
Xihang Shi, Yaniv Kurman, Michael Shentcis, Liang Jie Wong, F. Javier Garcia de Abajo, Ido Kaminer
Summary: The science and technology of X-ray optics have made significant progress, allowing for the focusing of X-rays in various applications. However, certain forms of tailoring waves that are common in the optical regime have been challenging to achieve in the X-ray regime. We propose a novel concept of X-ray focusing by inducing a curved wavefront during the X-ray generation process, enabling the creation of nanobeams with precise focal spots. This concept bypasses the limitations of traditional X-ray optical components and allows for tunable parameters of the focused hotspot.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Review
Physics, Applied
Qiong Ma, Roshan Krishna Kumar, Su-Yang Xu, Frank H. L. Koppens, Justin C. W. Song
Summary: Photocurrent can reveal the out-of-equilibrium properties of quantum materials and can be used to probe electronic states, quantum geometry, and quantum kinetics. It is sensitive to various physical processes across different spatiotemporal scales, making it a versatile probe for studying electronic states, quantum geometry, quantum kinetics, and device characteristics of quantum materials. This Technical Review outlines the key multiphysics principles of photocurrent diagnostics and its applications in resolving band structure, characterizing topological materials, and enabling new types of remote-sensing protocols and photocurrent nanoscopy.
NATURE REVIEWS PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Taoufiq Ouaj, Leonard Kramme, Marvin Metzelaars, Jiahan Li, Kenji Watanabe, Takashi Taniguchi, James H. Edgar, Bernd Beschoten, Paul Koegerler, Christoph Stampfer
Summary: This work demonstrates the growth of hBN crystals using an iron flux and their potential for high-performance hBN-graphene devices. The crystals can be detached from the metal using hydrochloric acid, and they exhibit excellent quality for van der Waals heterostructures. The thickness of exfoliated hBN flakes does not correlate with their quality in high mobility graphene devices.
Article
Multidisciplinary Sciences
M. Chen, Y. Zhong, E. Harris, J. Li, Z. Zheng, H. Chen, J. -S. Wu, P. Jarillo-Herrero, Q. Ma, J. H. Edgar, X. Lin, S. Dai
Summary: In this study, the authors propose a method to engineer material properties by repositioning isotopes in engineered van der Waals isotopic heterostructures. By varying the composition, stacking order, and thicknesses of h(10)BN and h(11)BN building blocks, the energy-momentum dispersions of hyperbolic phonon polaritons can be modulated. These tailored polaritons have promising applications in nanophotonics and thermal functionalities.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Alexey Falin, Haifeng Lv, Eli Janzen, James H. Edgar, Rui Zhang, Dong Qian, Hwo-Shuenn Sheu, Qiran Cai, Wei Gan, Xiaojun Wu, Elton J. G. Santos, Lu Hua Li
Summary: This study uses single-atom-thin hBN to investigate the mechanical properties of materials and finds that the lighter isotope 10B exhibits higher elasticity and strength compared to the heavier isotope 11B. This suggests that two-dimensional materials can be used to study the intrinsic mechanical properties of materials, and the normally neglected isotopic perturbation sometimes plays a more critical role than the isotopic mass effect in the mechanical and other physical properties. Two-dimensional materials can serve as good platforms for studying extremely subtle mechanical behaviors.
NATURE COMMUNICATIONS
(2023)
Article
Nanoscience & Nanotechnology
Sachin Sharma, Song Liu, James H. Edgar, Ioannis Chatzakis
Summary: Hexagonal boron nitride (hBN) is a semiconductor material with promising applications due to its strong luminescence. The dynamics of photogenerated carriers in hBN were analyzed, and Auger recombination and defect-assisted recombination were identified as the main mechanisms affecting carrier kinetics.
Article
Chemistry, Physical
Peter Udvarhelyi, Tristan Clua-Provost, Alrik Durand, Jiahan Li, James H. H. Edgar, Bernard Gil, Guillaume Cassabois, Vincent Jacques, Adam Gali
Summary: Researchers determine the coupling of boron-vacancy spin defect (V-B(-)) in hexagonal boron nitride (hBN) to strain and electric fields using first-principles calculations. Their work reveals the interplay between local piezoelectric and elastic effects in the response to electric fields. Theoretical predictions are used to analyze optically detected magnetic resonance (ODMR) spectra on hBN crystals with varying densities of V-B(-) centers, confirming that the orthorhombic zero-field splitting parameter is a result of local electric fields from surrounding charge defects. This study paves the way for applications of V-B(-) centers in quantitative electric field imaging and quantum sensing under pressure.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Eduardo J. C. Dias, Ivan Madan, Simone Gargiulo, Francesco Barantani, Michael Yannai, Giovanni Maria Vanacore, Ido Kaminer, Fabrizio Carbone, F. Javier Garcia de Abajo
Summary: We develop a comprehensive microscopic theory to predict the spatiotemporal dynamics of laser-pulse-induced plasmas, and study the characteristics of terahertz fields generated through electron emission, metal screening, and plasma cloud interactions. We also investigate the interaction with femtosecond electron beams and explain recent ultrafast electron microscopy experiments. Our work contributes fundamental insight into the generation and dynamics of micron-scale electron plasmas and their interaction with ultrafast electron pulses.
NANOSCALE ADVANCES
(2023)
Article
Materials Science, Multidisciplinary
Steffi Y. Woo, Alberto Zobelli, Robert Schneider, Ashish Arora, Johann A. Preuss, Benjamin J. Carey, Steffen Michaelis de Vasconcellos, Maurizia Palummo, Rudolf Bratschitsch, Luiz H. G. Tizei
Summary: The interlayer interaction of excitons in twisted van der Waals hetero- and homostructures is determined by the moire twist angle. The influence of twist angle on the excitonic absorption in twisted bilayer tungsten diselenide (WSe2) has been studied using electron energy-loss spectroscopy. Atomic-resolution imaging and spectral analysis revealed a blueshift in the high-energy excitonic peak C with increasing twist angle. The combined experiment/theory investigation provides valuable insight into the physical origins of high-energy absorption resonances in twisted bilayers.
Article
Optics
Yiming Pan, Eliahu Cohen, Ebrahim Karimi, Avraham Gover, Norbert Schonenberger, Tomas Chlouba, Kangpeng Wang, Saar Nehemia, Peter Hommelhoff, Ido Kaminer, Yakir Aharonov
Summary: In this study, a new measurement-based framework is developed to investigate classical and quantum interactions between free electrons and photons, and is experimentally tested. It is found that classical electron-photon interactions can be represented as outcomes of weak measurement. The transition from quantum to classical measurement is quantified by a universal factor.
LIGHT-SCIENCE & APPLICATIONS
(2023)
