A5007807640- Plasmonic and Surface Plasmon Research
- Near-Field Optical Microscopy
- Transition Metal Oxide Nanomaterials
- Photonic and Optical Devices
- Thermal Radiation and Cooling Technologies
- Quantum Dots Synthesis And Properties
- Terahertz technology and applications
- Mechanical and Optical Resonators
- Metamaterials and Metasurfaces Applications
- Graphene research and applications
- Silk-based biomaterials and applications
- Ga2O3 and related materials
- Gold and Silver Nanoparticles Synthesis and Applications
- Topological Materials and Phenomena
- 2D Materials and Applications
- Gas Sensing Nanomaterials and Sensors
- Electronic and Structural Properties of Oxides
- Magnetic and transport properties of perovskites and related materials
- Force Microscopy Techniques and Applications
- Strong Light-Matter Interactions
- Photoacoustic and Ultrasonic Imaging
- Advanced Condensed Matter Physics
- Photonic Crystals and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Spectroscopy and Laser Applications
Stony Brook University
2016-2025
Brookhaven National Laboratory
2020-2025
RIKEN BNL Research Center
2023
Weatherford College
2023
Binghamton University
2022
Yale University
2022
Columbia University
2017-2022
State University of New York
2022
National Center for Nanoscience and Technology
2017-2022
Suzhou Institute of Nano-tech and Nano-bionics
2022
Active, widely tunable optical materials have enabled rapid advances in photonics and optoelectronics, especially the emerging field of meta-devices. Here, we demonstrate that spatially selective defect engineering on nanometer scale can transform phase-transition into metasurfaces. Using ion irradiation through nanometer-scale masks, selectively defect-engineered insulator-metal transition vanadium dioxide, a prototypical correlated material whose properties change dramatically depending...
Control over charge carrier density provides an efficient way to trigger phase transitions and modulate the optoelectronic properties of materials. This approach can also be used induce topological in optical response photonic systems. Here we report a transition isofrequency dispersion contours hybrid polaritons supported by two-dimensional heterostructure consisting graphene α-phase molybdenum trioxide. By chemically changing doping level graphene, observed that topology polariton surfaces...
Abstract Label‐free super‐resolution (LFSR) imaging relies on light‐scattering processes in nanoscale objects without a need for fluorescent (FL) staining required super‐resolved FL microscopy. The objectives of this Roadmap are to present comprehensive vision the developments, state‐of‐the‐art field, and discuss resolution boundaries hurdles that be overcome break classical diffraction limit label‐free imaging. scope spans from advanced interference detection techniques, where...
Novel mechanisms for electromagnetic wave emission in the terahertz frequency regime emerging at nanometer scale have recently attracted intense attention purpose of searching next-generation broadband THz emitters. Here, we report emission, utilizing interface inverse Rashba-Edelstein effect. By engineering symmetry Ag/Bi Rashba interface, demonstrate a controllable radiation (∼0.1-5 THz) waveform emitted from metallic Fe/Ag/Bi heterostructures following photoexcitation. We further reveal...
A set of biocompatible, biodegradable, and biofunctionalizable diffractive optical elements (DOEs) using silk proteins as the building materials is reported. The diffraction pattern a DOE highly sensitive to surrounding environment structural integrity, offering numerous opportunities for biosensing applications.
Pump-probe spectroscopy is central for exploring ultrafast dynamics of fundamental excitations, collective modes and energy transfer processes. Typically carried out using conventional diffraction-limited optics, pump-probe experiments inherently average over local chemical, compositional, electronic inhomogeneities. Here we circumvent this deficiency introduce infrared with ~20 nm spatial resolution, far below the diffraction limit, which accomplished a scattering scanning near-field...
We investigated phonon–polaritons in hexagonal boron nitride—a naturally hyperbolic van der Waals material—by means of the scattering-type scanning near-field optical microscopy. Real-space nanoimages we have obtained detail how polaritons are launched when light incident on a thin nitride slab is scattered by various intrinsic and extrinsic inhomogeneities, including sample edges, metallic nanodisks deposited its top surface, random defects, surface impurities. The scanned tip microscope...
We report on time-resolved mid-infrared (mid-IR) near-field spectroscopy of the narrow bandgap semiconductor InAs. The dominant effect we observed pertains to dynamics photoexcited carriers and associated surface plasmons. A novel combination pump–probe techniques nanospectroscopy accesses high momentum plasmons demonstrates efficient, subpicosecond photomodulation plasmon dispersion with subsequent tens picoseconds decay under ambient conditions. photoinduced change probe intensity due in...
Infrared spectroscopy of VO${}_{2}$ thin films at high spatial resolution shows new electronic and lattice states due to epitaxial strain that differ fundamentally from those in the bulk. This is first ultra-broadband infrared near-field study a correlated electron material, made possible by newly developed synchrotron method (SINS) on Advanced Light Source Lawrence Berkeley National Laboratory.
Accessing the nonradiative near-field electromagnetic interactions with high in-plane momentum (q) is key to achieve super resolution imaging far beyond diffraction limit. At far-infrared and terahertz (THz) wavelengths (e.g., 300 μm = 1 4 meV), study of q response nanoscale still a nascent research field. In this work, we report on THz nanoimaging exfoliated single multilayer graphene flakes by using state-of-the-art scattering-type optical microscope (s-SNOM). We experimentally...
Abstract Silk protein fibres produced by silkworms and spiders are renowned for their unparalleled mechanical strength extensibility arising from high-β-sheet crystal contents as natural materials. Investigation of β-sheet-oriented conformational transitions in silk proteins at the nanoscale remains a challenge using conventional imaging techniques given limitations chemical sensitivity or limited spatial resolution. Here, we report on electron-regulated polymorphic revealed near-field...
Abstract Most van der Waals crystals present highly anisotropic optical responses due to their strong in-plane covalent bonding and weak out-of-plane interactions. However, the determination of polarization-dependent dielectric constants remains a nontrivial task, since size dimension samples are often below or close diffraction limit probe light. In this work, we apply an nano-imaging technique determine in representative crystals. Through study both ordinary extraordinary waveguide modes...
Modern scattering-type scanning near-field optical microscopy (s-SNOM) has become an indispensable tool in material research. However, as the s-SNOM technique marches into far-infrared (IR) and terahertz (THz) regimes, emerging experiments sometimes produce puzzling results. For example, "anomalies" contrast have been widely reported. In this Letter, we systematically investigate a series of extreme subwavelength metallic nanostructures via imaging GHz to THz frequency range. We find that is...
Manipulation of the propagation and energy-transport characteristics subwavelength infrared (IR) light fields is critical for application nanophotonic devices in photocatalysis, biosensing, thermal management. In this context, metamaterials are useful composite materials, although traditional metal-based structures constrained by their weak mid-IR response, while associated capabilities optical focusing limited size attainable artificial poor performance available active means control....
Due to the two-dimensional character of graphene, plasmons sustained by this material have been invariably studied in supported samples so far. The substrate provides stability for graphene but often causes undesired interactions (such as dielectric losses, phonon hybridization, and impurity scattering) that compromise quality limit intrinsic flexibility plasmons. Here, we demonstrate visualization suspended at room temperature, exhibiting high-quality factor Q~33 long propagation length > 3...
Abstract Excitons play a dominant role in the optoelectronic properties of atomically thin van der Waals (vdW) semiconductors. These excitons are amenable to on-demand engineering with diverse control knobs, including dielectric screening, interlayer hybridization, and moiré potentials. However, external stimuli frequently yield heterogeneous excitonic responses at nano- meso-scales, making their spatial characterization conventional diffraction-limited optics formidable task. Here, we use...
We report the topological electronic structure and magnetic magnetotransport properties of a noncentrosymmetric compound GdAlSi. Magnetic susceptibility shows an antiferromagnetic transition at ${T}_{\mathrm{N}}=32$ K. In-plane isothermal magnetization exhibits unusual hysteresis behavior higher field, rather than near zero field. Moreover, is asymmetric under positive negative fields. First-principles calculations were performed on various configurations, revealing that state ground state,...
Abstract Recent progress in ultrafast spectroscopy and semiconductor technology is enabling unique applications screening, detection, diagnostics the Terahertz (T‐ray) regime. The promise of efficaciously operation this spectral region tempered by lack devices that can spectrally analyze samples at sufficient temporal spatial resolution. Real‐time, multispectral T‐ray (Mul‐T) imaging reported designing demonstrating hyperspectral metamaterial focal plane array (MM‐FPA) interfaces allowing...
Electronic, magnetic, and structural phase inhomogeneities are ubiquitous in strongly correlated quantum materials. The characteristic length scales of the can range from atomic to mesoscopic, depending on their microscopic origins as well various sample dependent factors. Therefore, progress with understanding phenomena critically depends experimental techniques suitable provide appropriate spatial resolution. This requirement is difficult meet for some most informative methods condensed...
Abstract Precise patterning of polymer‐based biomaterials for functional bio‐nanostructures has extensive applications including biosensing, tissue engineering, and regenerative medicine. Remarkable progress is made in both top‐down (based on lithographic methods) bottom‐up (via self‐assembly) approaches with natural synthetic biopolymers. However, most methods only yield 2D pseudo‐3D structures restricted geometries functionalities. Here, it reported that precise nanostructuring genetically...