A5101714269- Graphene research and applications
- Quantum and electron transport phenomena
- Photonic and Optical Devices
- Advanced Fiber Laser Technologies
- Gyrotron and Vacuum Electronics Research
- Photorefractive and Nonlinear Optics
- Magnetic properties of thin films
- Advanced Frequency and Time Standards
- Particle Accelerators and Free-Electron Lasers
- Physics of Superconductivity and Magnetism
- Thermal properties of materials
- Laser-Plasma Interactions and Diagnostics
- 2D Materials and Applications
- Advanced Thermoelectric Materials and Devices
- Laser Design and Applications
- Magnetic Field Sensors Techniques
- Thermal Radiation and Cooling Technologies
- Ga2O3 and related materials
- Pulsed Power Technology Applications
- Laser Material Processing Techniques
- Pulsars and Gravitational Waves Research
- Geophysics and Sensor Technology
- Topological Materials and Phenomena
- Advanced Data Storage Technologies
- Photovoltaic System Optimization Techniques
Stanford University
2012-2021
Wuhan University
2015-2019
Data Storage Institute
2006-2013
Agency for Science, Technology and Research
2010-2013
National University of Singapore
2010-2011
We propose a simple, yet highly efficient and robust device for producing valley polarized current in graphene. The comprises of two distinct components; region uniform uniaxial strain, adjacent to an out-of-plane magnetic barrier configuration formed by patterned ferromagnetic stripes. show that when the amount field strength, Fermi level are properly tuned, output can be made consist only single contribution. Perfect filtering is achievable within experimentally accessible parameters.
Thermal conduction in periodic multilayer composites can be strongly influenced by nonequilibrium electron–phonon scattering for periods shorter than the relevant free paths. Here we argue that two additional mechanisms—quasiballistic phonon transport normal to metal film and inelastic electron-interface scattering—can also impact metal/dielectric multilayers with a period below 10 nm. Measurements use 3ω method six different bridge widths down 50 nm extract in- cross-plane effective...
Using an 800 nm, 45 fs pulse-front-tilted laser we demonstrate a record 315 keV energy gain in dual grating dielectric accelerator (DLA) and average accelerating gradients of 560 MV/m over 0.5 mm. These results open new regime DLA characterized by significant evolution the beam distribution longitudinal phase space, corresponding to >1/4 synchrotron oscillation. By tilting wavefront control resonant velocity observe net gain, indicating that tapered optical could be used achieve very high gain.
We propose an on-chip optical power delivery system for dielectric laser accelerators based on a fractal 'tree-branch' waveguide network. This replaces experimentally demanding free-space manipulations of the driving beam with chip-integrated techniques precise nano-fabrication, enabling access to orders magnitude increases in interaction length and total energy gain these miniature accelerators. Based computational modeling, relativistic regime, our is estimated provide 21 keV over...
The electronic properties of armchair graphene nanoribbons (AGNRs) can be significantly modified from semiconducting to metallic states by applying a uniform perpendicular magnetic field (B-field). Here, we theoretically study the band gap modulation induced B-field. applied B-field causes lowest conduction subband and topmost valence move closer one another form n=0 Landau level. We exploit this effect realize device relevant magnetoresistive (MR) modulation. Unlike in conventional...
We propose a dielectric laser accelerator design based on tapered slot waveguide structure for sub-relativistic electron acceleration. This tapering scheme allows straightforward tuning of the phase velocity accelerating field along propagation direction, which is necessary maintaining synchronization with electrons as their velocities increase. Furthermore, non-resonant nature this better tolerance to experimental errors. also introduce method continuously eikonal approximation, and give...
We study the weakly guided silicon nitride waveguide as an on-chip power delivery solution for dielectric laser accelerators (DLAs). focus on two main limiting factors network DLAs: optical damage and nonlinear characteristics. The typical delivered fluence at onset of is measured to be ∼0.19 J/cm2 a 2 μm central wavelength 250 fs pulse width. This lower than that bulk Si3N4 (∼0.65 J/cm2), but higher (∼0.17 J/cm2). also report nonlinearity-induced spectrum phase variance output this...
Studying the influence of demand response and dynamic characteristics battery energy storage on configuration optimal operation system (BESS) in Wind-Photovoltaic (PV)-Energy Storage (ES) hybrid microgrid. A model that is based electricity price elasticity established time-of-use price. Take capital-operating cost direct economic benefit BESS loss abandoned photovoltaic wind power as optimization objective, an method considers maximum absorption proposed while using particle swarm to solve....
We present a method for 3D sub-nanometer displacement measurement using set of differential optical shadow sensor. It is based on pairs collimated beams opposite sides an object that are partially blocked by it. Applied to sphere, our 3-axis sensor module consists 8 parallel beam-detector sets redundancy. The sphere blocks half each beam power in the nominal centered position, and any can be measured changes amongst detectors. have experimentally demonstrated sensitivity 0.87 nm/rtHz at 1 Hz...
We study Klein tunneling across a PN junction in monolayer graphene (MLG) and the AB-bilayer (BLG) under effect of perpendicular magnetic-field (B-field). In process, normally incident electrons MLG are fully transmissive (reflective) upon hitting barrier. When finite B-field is applied, transmission suppressed over an energy range around barrier height, effectively opening gap. This suppression may be attributed to magnetic deflection arising from Lorentz force, which shifts profile device...
We show a large magnetoresistance (MR) effect in graphene heterostructure consisting of metallic and semiconductor-type armchair-graphene-nanoribbon. In the heterostructure, transmission across first subband semiconducting armchair-graphene-nanoribbon is forbidden under zero magnetic-field, due to orthogonality wavefunctions. A finite magnetic-field introduces quantum hall-like effect, which distorts Thus, occurs heterojunction, giving rise MR effect. study dependence this on temperature...
In this paper we present a method for obtaining accurate finesse by recovering the Lorentzian profile of cavity resonances with laser continuously locked to and apply it weak gas absorption measurements. The technique was implemented on our noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) experimental setup. measurement is performed in cavity-locked regime, leading high repeatability easy automation. involves locking carrier fundamental mode sweeping second...
The unique properties of gallium oxide (GaOx) have drawn increasing interest as a material suitable for high-power electronic and optical applications. Herein, we report the demonstration low-loss GaOx-core/SiO2-cladding waveguides on Si substrate. We present fabrication process annealing treatments waveguide devices, characterize corresponding effects transmission 3 common wavelengths: 633 nm, 1064 1550 nm. best propagation loss achieved these wavelengths is measured to be -0.4±0.1dB/cm,...
Dielectric Laser Acceleration (DLA) achieves the highest gradients among structure-based electron accelerators. The use of dielectrics increases breakdown field limit, and thus achievable gradient, by a factor at least 10 in comparison to metals. Experimental demonstrations DLA 2013 led Accelerator on Chip International Program (ACHIP), funded Gordon Betty Moore Foundation. In ACHIP, our main goal is build an accelerator silicon chip, which can accelerate electrons from below 100 keV above 1...
A large magnetoresistance effect is obtained at room-temperature by using p-i-n armchair-graphene-nanoribbon (GNR) heterostructures. The key advantage the virtual elimination of thermal currents due to presence band gaps in contacts. current B=0T greatly decreased while B>0T relatively band-to-band tunneling effects, resulting a high ratio, even room-temperature. Moreover, we explore effects edge-roughness, length, and width GNR channels on device performance. An increase edge-roughness...
A track width reduction and an area resistance (RA) scheme are presented to meet the requirement of reader for ultrahigh density recording. The side reading effect worsens performance track-width-gradient-reduction design even if a side-shield layer is applied due overlap between backend side-shield. However, side-reading can be significantly suppressed in long-height after introduction Using sensor design, RA, signal level may ultra-high back flux-guide further improve sensitivity tunneling...
We discuss how photonic control addresses key challenges of dielectric laser accelerators (DLAs) and propose applications using DLAs, i.e., electron pulse compression quantum sensing two-level systems.
As the recording density of hard disk increases, smaller reader track width is required. The tunneling GMR which has been used in drive potential for lTb/in2 due to its large MR ratio. To maintain SNR and match impedance preamplifier, low RA less than 0.5 Omegamum <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> However, 1 difficult achieve both thickness barrier height limitation. On other hand, as reduces, side reading effect will...
We show that a moderately strong constant electric field in the plane of monolayer graphene sheet can create particle-hole pairs at an observable rate. The undergo zitterbewegung opposite directions leading to Hall-like separation charge carriers and measurable transverse dipole moment is predicted which serves as signature zitterbewegung. In contrast with created pairs, zero modes excitation induce current but do not result separated charges. For bilayer similar effect by shown be possible.
A read sensor working in the toggle mode is presented. The free layer comprises a balanced synthetic-antiferromagnetic (SAF) multilayer. magnetization of SAF perpendicular to air-bearing surface (ABS) when bias field applied direction ABS. reference fixed be parallel ABS instead as conventional case. sensitivity (for small track width) improves significantly compared abutted junction type. For with long height structure, performance both and linearity has also been improved because increased...
Output power of Photovoltaic generation system is influenced by temperature, humidity, solar radiation intensity and so on.The effects three kinds external climate conditions, including intensity, on photovoltaic output were anal sized in detail this paper, then similar days for prediction selected based grey relational analysis.The quantum particle swarm optimization method optimizing kernel parameters support vector machine was immediately introduced.In line with the data function, a new...
We obtain zero modes of bilayer graphene (BG) with a kink potential. Such solutions have topologically robust properties. study fractional charge in BG the trigonal interaction and discuss possible detection..
PROCEEDINGS PAPER Electron-Phonon Coupled Two-Dimensional Heat Transfer in Nanoscale Metal/Dielectric Multilayers Zijian Li, Li Stanford University, Stanford, CA Search for other works by this author on: This Site PubMed Google Scholar Si Tan, Tan Takashi Kodama, Kodama Elah Bozorg-Grayeli, Bozorg-Grayeli Mehdi Asheghi, Asheghi Kenneth E. Goodson Author Information Paper No: HT2012-58350, pp. 579-587; 9 pages https://doi.org/10.1115/HT2012-58350 Published Online: July 24, 2013