Browsing by Author "Kaxiras, Efthimios"

Now showing items 21-40 of 60

    • Enhancement of Interlayer Exchange in an Ultrathin Two-Dimensional Magnet 

      Klein, Dahlia; MacNeill, David; Song, Qian; Larson, Daniel; Fang, Shiang; Xu, Mingyu; Ribeiro, R. A.; Canfield, P. C.; Kaxiras, Efthimios; Comin, Riccardo; Jarillo-Herrero, Pablo (Springer Science and Business Media LLC, 2019-09-16)
      Following the recent isolation of monolayer CrI3 [1], there has been a surge of new two-dimensional van der Waals magnetic materials [2-12], whose incorporation in van der Waals heterostructures offers a new platform for ...

    • Enhancement of Interlayer Exchange in an Ultrathin Two-Dimensional Magnet 

      Song, Qian; Fang, Shiang; Xu, Mingyu; Ribeiro, R. A.; Canfield, P. C.; Kaxiras, Efthimios; Comin, Riccardo; Jarillo-Herrero, Pablo; Klein, Dahlia; MacNeill, David; Larson, Daniel; Canfield, P; Comin, Riccardo (Springer Science and Business Media LLC, 2019-09-16)
      Following the recent isolation of monolayer CrI3, many more two-dimensional van der Waals magnetic materials have been isolated. Their incorporation in van der Waals heterostructures offers a new platform for spintronics ...

    • Epitaxial Growth of Molecular Crystals on van der Waals Substrates for High-Performance Organic Electronics 

      Lee, Chul-Ho; Schiros, Theanne; Santos, Elton J. G.; Kim, Bumjung; Yager, Kevin G.; Kang, Seok Ju; Lee, Sunwoo; Yu, Jaeeun; Watanabe, Kenji; Taniguchi, Takashi; Hone, James; Kaxiras, Efthimios; Nuckolls, Colin; Kim, Philip (Wiley-VCH Verlag Berlin, 2014)
      Epitaxial van der Waals (vdW) heterostructures of organic and layered materials are demonstrated to create high-performance organic electronic devices. High-quality rubrene films with large single-crystalline domains are ...

    • Establishing the limits of efficiency of perovskite solar cells from first principles modeling 

      Grånäs, Oscar; Vinichenko, Dmitry; Kaxiras, Efthimios (Nature Publishing Group, 2016)
      The recent surge in research on metal-halide-perovskite solar cells has led to a seven-fold increase of efficiency, from ~3% in early devices to over 22% in research prototypes. Oft-cited reasons for this increase are: (i) ...

    • Exploring Biomolecular Interactions Through Single-Molecule Force Spectroscopy and Computational Simulation 

      Yang, Darren (2016-04-11)
      Molecular interactions between cellular components such as proteins and nucleic acids govern the fundamental processes of living systems. Technological advancements in the past decade have allowed the characterization of ...

    • First-Principles Multiscale Investigation of Structural and Chemical Defects in Metals 

      Schusteritsch, Georg (2013-03-08)
      This thesis explores multiscale approaches to describe structural and chemical defects in metals. Particular emphasis is placed on investigating processes involving grain boundaries (GBs) in combination with impurity and ...

    • A Flexible High-Performance Lattice Boltzmann GPU Code for the Simulations of Fluid Flows in Complex Geometries 

      Bernaschi, Massimo; Fatica, Massimiliano; Melchionna, Simone; Succi, Sauro; Kaxiras, Efthimios (Wiley-Blackwell, 2010)
      We describe the porting of the Lattice Boltzmann component of MUPHY, a multi-physics/scale simulation software, to multiple graphics processing units using the Compute Unified Device Architecture. The novelty of this work ...

    • Graphene Hydrate: Theoretical Prediction of a New Insulating Form of Graphene 

      Wang, Wei Li; Kaxiras, Efthimios (IOP Publishing, 2010)
      Using first-principles calculations, we show that the formation of carbohydrates directly from carbon and water is energetically favored when graphene is subjected to an unequal chemical environment across the two sides, ...

    • Ground State of the Strong-Coupling Hubbard Hamiltonian: A Numerical Diagonalization Study 

      Kaxiras, Efthimios; Menousakis, Efstratios (American Physical Society, 1988)
      We exactly diagonalize the effective Hamiltonian obtained from the Hubbard model in the strong-coupling limit for a two-dimensional sqrt[10]×sqrt[10] size square lattice. The effective Hamiltonian operates on a restricted ...

    • Heterointerface Effects in the Electro-Intercalation of Van Der Waals Heterostructures 

      Kim, Philip; Rezaee, Mehdi; Yoo, Hyobin; Larson, Daniel; Zhao, Frank; Taniguchi, Takashi; Watanabe, Kenji; Brower-Thomas, Tina; Kaxiras, Efthimios; Bediako, Kwabena (Springer Nature, 2018-06-21)
      Molecular-scale manipulation of electronic/ionic charge accumulation in materials is a preeminent challenge, particularly in electrochemical energy storage. Layered van der Waals (vdW) crystals exemplify a diverse family ...

    • Hole Dynamics in the Two-Dimensional Strong-Coupling Hubbard Hamiltonian 

      Kaxiras, Efthimios; Menousakis, Efstratios (American Physical Society, 1988)
      The effective Hamiltonian, obtained from the Hubbard model in the strong-coupling limit, is diagonalized exactly for a periodic two-dimensional square lattice of ten sites. We obtain the ground state of the system for any ...

    • Hydrogenation of Semiconductor Surfaces: Si and Ge (111) 

      Kaxiras, Efthimios; Joannopoulos, John D. (American Physical Society, 1988)
      The relaxations of hydrogenated Si and Ge (111) surfaces are determined using ab initio self-consistent calculations in a slab configuration. The Si-H and Ge-H bonds are found to be considerably larger than the sum of ...

    • Hydrokinetic Approach to Large-Scale Cardiovascular Blood Flow 

      Melchionna, Simone; Bernaschi, Massimo; Succi, Sauro; Kaxiras, Efthimios; Rybicki, Frank John; Mitsouras, Dimitris; Coskun, Ahmet U.; Feldman, Charles Lawrence (Elsevier, 2010)
      We present a computational method for commodity hardware-based clinical cardiovascular diagnosis based on accurate simulation of cardiovascular blood flow. Our approach leverages the flexibility of the Lattice Boltzmann ...

    • Hyperon Radiative Decay 

      Kaxiras, Efthimios; Moniz, Ernest J.; Soyeur, Madeleine (American Physical Society, 1985)
      The radiative decay widths of the low-lying strange baryons are calculated both within the relativistic quark bag model and the nonrelativistic potential model. These widths are found to depend sensitively upon the quark-model ...

    • Insights from Theory on the Relationship between Surface Reactivity and Gold Atom Release 

      Baker, Thomas A.; Kaxiras, Efthimios; Friend, Cynthia M. (Springer Nature, 2010)
      Density functional theory, informed by experimental studies, is used to investigate the interplay of surface morphology, the adsorption site of reactants, the nature of the interaction between adsorbates and the surface, ...

    • Insights into reactivity and defect properties of semiconductor surfaces from first-principles computations 

      Vinichenko, Dmitry (2016-07-14)
      We use first-principles computations based on Ehrenfest dynamics and density functional theory to study water and methanol photo-oxidation on a model photo-catalytic material – the (110) surface of rutile titanium dioxide. ...

    • Investigating Non-Periodic Solids Using First Principles Calculations and Machine Learning Algorithms 

      Çubuk, Ekin Doğuş (2016-05-18)
      Computational methods are expected to play an increasingly important role in materials design. In order to live up to these expectations, simulations need to have predictive power. To achieve this, there are two hurdles, ...

    • Is the Nature of Magnetic Order in Copper-Oxides and in Iron-Pnictides Different? 

      Manousakis, Efstratios; Ren, Jun; Meng, Sheng; Kaxiras, Efthimios (Elsevier, 2010)
      We use the results of first-principles electronic structure calculations and a strong coupling perturbation approach, together with general theoretical arguments, to illustrate the differences in super-exchange interactions ...

    • Local Bonding Effects in the Oxidation of CO on Oxygen-Covered Au(111) from Ab Initio Molecular Dynamics Simulations 

      Baker, Thomas A.; Friend, Cynthia M.; Kaxiras, Efthimios (American Chemical Society (ACS), 2010)
      A fully dynamical approach using ab initio molecular dynamics (AIMD) simulations is applied to the investigation of CO oxidation on O-covered Au(111). We investigate how the activity of gold depends upon temperature, oxygen ...

    • Magnetic resonance spectroscopy of an atomically thin material using a single-spin qubit 

      Lovchinsky, Igor; Lukin, Mikhail D.; Sanchez-Yamagishi, Javier; Urbach, Elana Kahn; Choi, Soonwon; Fang, Shiang; Andersen, Trond Ikdahl; Watanabe, Kenji; Taniguchi, Takashi; Bylinskii, Alexei; Kaxiras, Efthimios; Kim, Philip; Park, Hongkun (American Association for the Advancement of Science (AAAS), 2017)
      Two-dimensional (2D) materials offer a promising platform for exploring condensed matter phenomena and developing technological applications. However, the reduction of material dimensions to the atomic scale poses a challenge ...