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Full-Text Articles in Physics

Data Supporting The Paper "Aerosol Mediated Glaciation Of Mixed-Phase Clouds: Steady-State Laboratory Measurements", N. Desai, K. K. Chandrakar, G. Kinney, W. Cantrell, R. A. Shaw Jun 2019

Data Supporting The Paper "Aerosol Mediated Glaciation Of Mixed-Phase Clouds: Steady-State Laboratory Measurements", N. Desai, K. K. Chandrakar, G. Kinney, W. Cantrell, R. A. Shaw

Department of Physics Publications

No abstract provided.


Tailoring Of The Electronic Property Of Zn-Btc Metal–Organic Framework Via Ligand Functionalization: An Ab Initio Investigation, Gemechis Degaga, Ravindra Pandey, Chansi Gupta, Lalit Bharadwaj May 2019

Tailoring Of The Electronic Property Of Zn-Btc Metal–Organic Framework Via Ligand Functionalization: An Ab Initio Investigation, Gemechis Degaga, Ravindra Pandey, Chansi Gupta, Lalit Bharadwaj

Department of Physics Publications

Metal–organic frameworks (MOFs) are porous materials of recent interest due to their promising properties for technological applications. In this paper, the structure–property relationships of pristine and functionalized Zn-BTC (Zn3(BTC)2) MOFs are investigated. The results based on density functional theory (DFT) find that MOFs with coordinatively saturated secondary building units (SBU) are metallic, and MOFs with coordinatively unsaturated SBU are semi-conducting. The ligand functionalization with electron acceptor (cyano-) and electron donor (amino-) groups appears to tailor the electronic properties of Zn-BTC MOFs; amino-functionalization led to a significant upward shift of the band-edges whereas cyano-functionalization ...


Leidenfrost Pattern Formation And Boiling, Prasanth Prabhakaran, Alexei Krekhov, Eberhard Bodenschatz, Stephan Weiss Apr 2019

Leidenfrost Pattern Formation And Boiling, Prasanth Prabhakaran, Alexei Krekhov, Eberhard Bodenschatz, Stephan Weiss

Department of Physics Publications

We report on Leidenfrost patterns and boiling with compressed sulfur hexafluoride ( SF6). The experiments were carried out in a large aspect ratio Rayleigh–Bénard convection cell, where the distance between the horizontal plates is comparable with the capillary length of the working fluid. Pressures and temperatures were chosen such that the bottom plate was above and the top plate was below the liquid–vapor transition temperature of SF6. As a result, SF6 vapor condenses at the top plate and forms drops that grow in size. Leidenfrost patterns are formed as the drops do not fall but levitate ...


The Dawn Of Non-Hermitian Optics, Ramy El-Ganainy, Mercedeh Khajavikhan, Demetrios Christodoulides, Sahin Ozdemir Mar 2019

The Dawn Of Non-Hermitian Optics, Ramy El-Ganainy, Mercedeh Khajavikhan, Demetrios Christodoulides, Sahin Ozdemir

Department of Physics Publications

Recent years have seen a tremendous progress in the theory and experimental implementations of non-Hermitian photonics, including all-lossy optical systems as well as parity-time symmetric systems consisting of both optical loss and gain. This progress has led to a host of new intriguing results in the physics of light–matter interactions with promising potential applications in optical sciences and engineering. In this comment, we present a brief perspective on the developments in this field and discuss possible future research directions that can benefit from the notion of non-Hermitian engineering.


Data Supporting The Paper "Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations", Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn R. Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra Dubey, Allison Aiken, Rajan K. Chakrabarty, Hans Moosmüller, Timothy B. Onasch, Rahul A. Zaveri, Barbara Scarnato, Paolo Fialho, Claudio Mazzoleni Feb 2019

Data Supporting The Paper "Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations", Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn R. Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra Dubey, Allison Aiken, Rajan K. Chakrabarty, Hans Moosmüller, Timothy B. Onasch, Rahul A. Zaveri, Barbara Scarnato, Paolo Fialho, Claudio Mazzoleni

Department of Physics Publications

No abstract provided.


Natural Graphite Cuboids, Andrey Korsakov, Olga V. Rezvukhina, John Jaszczak, Dmitriy I. Rezvukhin, Denis Mikhailenko Feb 2019

Natural Graphite Cuboids, Andrey Korsakov, Olga V. Rezvukhina, John Jaszczak, Dmitriy I. Rezvukhin, Denis Mikhailenko

Department of Physics Publications

Graphite cuboids are abundant in ultrahigh-pressure metamorphic rocks and are generally interpreted as products of partial or complete graphitization of pre-existing diamonds. The understanding of the graphite cuboid structure and its formation mechanisms is still very limited compared to nanotubes, cones, and other carbon morphologies. This paper is devoted to the natural occurrences of graphite cuboids in several metamorphic and magmatic rocks, including diamondiferous metamorphic assemblages. The studied cuboids are polycrystalline aggregates composed either of numerous smaller graphite cuboids with smooth surfaces or graphite flakes radiating from a common center. Silicates, oxides, and sulphides are abundant in all the samples ...


Data Supporting The Paper "Scaling Of An Atmospheric Model To Simulate Turbulence And Cloud Microphysics In The Pi Chamber", Subin Thomas, Mikhail S. Ovchinnikov, Fan Yang, Dennis Van Der Voort, Will Cantrell, Steven K. Krueger, Raymond Shaw Feb 2019

Data Supporting The Paper "Scaling Of An Atmospheric Model To Simulate Turbulence And Cloud Microphysics In The Pi Chamber", Subin Thomas, Mikhail S. Ovchinnikov, Fan Yang, Dennis Van Der Voort, Will Cantrell, Steven K. Krueger, Raymond Shaw

Department of Physics Publications

No abstract provided.


Winding Around Non-Hermitian Singularities, Qi Zhong, Mercedeh Khajavikhan, Demetrios Christodoulides, Ramy El-Ganainy Nov 2018

Winding Around Non-Hermitian Singularities, Qi Zhong, Mercedeh Khajavikhan, Demetrios Christodoulides, Ramy El-Ganainy

Department of Physics Publications

Non-Hermitian singularities are ubiquitous in non-conservative open systems. Owing to their peculiar topology, they can remotely induce observable effects when encircled by closed trajectories in the parameter space. To date, a general formalism for describing this process beyond simple cases is still lacking. Here we develop a general approach for treating this problem by utilizing the power of permutation operators and representation theory. This in turn allows us to reveal a surprising result that has so far escaped attention: loops that enclose the same singularities in the parameter space starting from the same point and traveling in the same direction ...


Fine-Scale Droplet Clustering In Atmospheric Clouds: 3d Radial Distribution Function From Airborne Digital Holography, Michael L. Larsen, Raymond Shaw, Alexander Kostinski, Susanne Glienke Nov 2018

Fine-Scale Droplet Clustering In Atmospheric Clouds: 3d Radial Distribution Function From Airborne Digital Holography, Michael L. Larsen, Raymond Shaw, Alexander Kostinski, Susanne Glienke

Department of Physics Publications

The extent of droplet clustering in turbulent clouds has remained largely unquantified, and yet is of possible relevance to precipitation formation and radiative transfer. To that end, data gathered by an airborne holographic instrument are used to explore the three-dimensional spatial statistics of cloud droplet positions in homogeneous stratiform boundary-layer clouds. The three-dimensional radial distribution functions g(r) reveal unambiguous evidence of droplet clustering. Three key theoretical predictions are observed: the existence of positive correlations, onset of correlation in the turbulence dissipation range, and monotonic increase of g(r) with decreasing r. This implies that current theory captures the essential ...


Turbulence Induced Cloud Voids: Observation And Interpretation, Katarzyna Karpinska, Jonathan F. E. Bodenschatz, Szymon P. Malinowski, Jakub L. Nowak, Steffen Risius, Tina Schmeissner, Raymond Shaw, Holger Siebert, Hengdong Xi, Haitao Xu, Eberhard Bodenschatz Oct 2018

Turbulence Induced Cloud Voids: Observation And Interpretation, Katarzyna Karpinska, Jonathan F. E. Bodenschatz, Szymon P. Malinowski, Jakub L. Nowak, Steffen Risius, Tina Schmeissner, Raymond Shaw, Holger Siebert, Hengdong Xi, Haitao Xu, Eberhard Bodenschatz

Department of Physics Publications

The phenomenon of cloud voids, i.e., elongated volumes inside a cloud that are devoid of droplets, was observed with laser sheet photography in clouds at a mountain-top station. Two experimental cases, similar in turbulence conditions yet with diverse droplet size distributions and cloud void prevalence, are reported. A theoretical explanation is proposed based on the study of heavy inertial sedimenting particles inside a Burgers vortex. A general conclusion regarding void appearance is drawn from theoretical analysis. Numerical simulations of polydisperse droplet motion with realistic vortex parameters and Mie scattering visual effects accounted for can explain the presence of voids ...


Data Supporting The Paper "Turbulence Induced Cloud Voids: Observation And Interpretation", Katarzyna Karpinska, Jonathan F. E. Bodenschatz, Szymon P. Malinowski, Jakub L. Nowak, Steffen Risius, Tina Schmeissner, Raymond Shaw, Holger Siebert, Hengdong Xi, Haitao Xu, Eberhard Bodenschatz Oct 2018

Data Supporting The Paper "Turbulence Induced Cloud Voids: Observation And Interpretation", Katarzyna Karpinska, Jonathan F. E. Bodenschatz, Szymon P. Malinowski, Jakub L. Nowak, Steffen Risius, Tina Schmeissner, Raymond Shaw, Holger Siebert, Hengdong Xi, Haitao Xu, Eberhard Bodenschatz

Department of Physics Publications

No abstract provided.


Dispersion Aerosol Indirect Effect In Turbulent Clouds: Laboratory Measurements Of Effective Radius, K. K. Chandrakar, Will Cantrell, A. Kostinski, Raymond Shaw Sep 2018

Dispersion Aerosol Indirect Effect In Turbulent Clouds: Laboratory Measurements Of Effective Radius, K. K. Chandrakar, Will Cantrell, A. Kostinski, Raymond Shaw

Department of Physics Publications

Cloud optical properties are determined not only by the number density nd and mean radiusof cloud droplets but also by the shape of the droplet size distribution. The change in cloud optical depth with changing nd, due to the change in distribution shape, is known as the dispersion effect. Droplet relative dispersion is defined as d=σr / ṝ . For the first time, a commonly used effective radius parameterization is tested in a controlled laboratory environment by creating a turbulent cloud. Stochastic condensation growth suggests d independent of nd for a nonprecipitating cloud, hence nearly ...


Organization And Oscillations In Simulated Shallow Convective Clouds, Guy Dagan, Ilan Koren, Alexander Kostinski, Orit Altaratz Sep 2018

Organization And Oscillations In Simulated Shallow Convective Clouds, Guy Dagan, Ilan Koren, Alexander Kostinski, Orit Altaratz

Department of Physics Publications

Physical insights into processes governing temporal organization and evolution of cloud fields are of great importance for climate research. Here using large eddy simulations with a bin microphysics scheme, we show that warm convective cloud fields exhibit oscillations with two distinct periods (~10 and ~90 min, for the case studied here). The shorter period dominates the nonprecipitating phase, and the longer period is related to the precipitating phase. We show that rain processes affect the domain's thermodynamics, hence forcing the field into a low‐frequency recharge‐discharge cycle of developing cloudiness followed by precipitation‐driven depletion. The end result ...


Data Supporting The Paper "Dispersion Aerosol Indirect Effect In Turbulent Clouds: Laboratory Measurements Of Effective Radius", K. K. Chandrakar, Will Cantrell, A. Kostinski, R. A. Shaw Sep 2018

Data Supporting The Paper "Dispersion Aerosol Indirect Effect In Turbulent Clouds: Laboratory Measurements Of Effective Radius", K. K. Chandrakar, Will Cantrell, A. Kostinski, R. A. Shaw

Department of Physics Publications

No abstract provided.


Simulation Data Supporting The Paper "Optical Properties And Radiative Forcing Of Fractal-Like Tar Ball Aggregates From Biomass Burning", Janarjan Bhandari, Swarup China, Giulia Girotto, Barbara Scarnato, Kyle Gorkowski, Allison Aiken, Manvendra Dubey, C. Mazzoleni Aug 2018

Simulation Data Supporting The Paper "Optical Properties And Radiative Forcing Of Fractal-Like Tar Ball Aggregates From Biomass Burning", Janarjan Bhandari, Swarup China, Giulia Girotto, Barbara Scarnato, Kyle Gorkowski, Allison Aiken, Manvendra Dubey, C. Mazzoleni

Department of Physics Publications

Simulations data supporting the paper "Optical properties and radiative forcing of fractal-like tar ball aggregates from biomass burning," to be submitted to the Journal of Quantitative Spectroscopy and Radiative Transfer.


Observation Of A Link Between Energy Dissipation Rate And Oscillation Frequency Of The Large-Scale Circulation In Dry And Moist Rayleigh-Bénard Turbulence, Dennis Niedermeier, Kelken Chang, Will Cantrell, Kamal Kant Chandrakar, David Ciochetto, Raymond Shaw Aug 2018

Observation Of A Link Between Energy Dissipation Rate And Oscillation Frequency Of The Large-Scale Circulation In Dry And Moist Rayleigh-Bénard Turbulence, Dennis Niedermeier, Kelken Chang, Will Cantrell, Kamal Kant Chandrakar, David Ciochetto, Raymond Shaw

Department of Physics Publications

In this study both the small- and large-scale flow properties of turbulent Rayleigh-Bénard convection are investigated. Experiments are carried out using the Π chamber (aspect ratio Γ=2) for Rayleigh number range Ra∼108–109 and Prandtl number Pr≈0.7. Furthermore, experiments are run for dry and wet conditions, i.e., top and bottom surfaces of the chamber are dry and wet, respectively. For wet conditions we further distinguish between conditions with and without the presence of sodium chloride aerosol particles which, if supersaturated conditions are achieved, lead to cloud droplet formation. We therefore refer to these ...


On The Detection Of Statistical Heterogeneity In Rain Measurements, A. R. Jameson, Michael L. Larsen, A. Kostinski Jul 2018

On The Detection Of Statistical Heterogeneity In Rain Measurements, A. R. Jameson, Michael L. Larsen, A. Kostinski

Department of Physics Publications

The application of the Wiener–Khintchine theorem for translating a readily measured correlation function into the variance spectrum, important for scale analyses and for scaling transformations of data, requires that the data be wide-sense homogeneous (stationary), that is, that the first and second moments of the probability distribution of the variable are the same at all times (stationarity) or at all locations (homogeneity) over the entire observed domain. This work provides a heuristic method independent of statistical models for evaluating whether a set of data in rain is wide-sense stationary (WSS). The alternative, statistical heterogeneity, requires 1) that there be ...


Scaling Of Drizzle Virga Depth With Cloud Thickness For Marine Stratocumulus Clouds, Fan Yang, Edward P. Luke, Pavlos Kollias, Alexander Kostinski, Andrew M. Vogelmann Apr 2018

Scaling Of Drizzle Virga Depth With Cloud Thickness For Marine Stratocumulus Clouds, Fan Yang, Edward P. Luke, Pavlos Kollias, Alexander Kostinski, Andrew M. Vogelmann

Department of Physics Publications

Drizzle is frequently observed in marine stratocumulus clouds and plays a crucial role in cloud lifetime and the radiation budget. Most drizzling stratocumulus clouds form drizzle virga below cloud base, where subcloud scavenging and evaporative cooling are important. We use unique ground‐based cloud radar observations (1) to examine the statistical properties of drizzle frequency and virga depth and (2) to test a simple analytical relationship derived between drizzle virga thickness (Hv) and cloud thickness (Hc). Observations show that 83% of marine stratocumulus clouds are drizzling although only 31% generate surface precipitation. The analytical expression for Hv ...


Topological Hybrid Silicon Microlasers, Han Zhao, Pei Mao University Of Pennsylvania, Mohammad H. Teimourpour, Simon Malzard, Ramy El-Ganainy, Henning Schomerus, Liang Feng Mar 2018

Topological Hybrid Silicon Microlasers, Han Zhao, Pei Mao University Of Pennsylvania, Mohammad H. Teimourpour, Simon Malzard, Ramy El-Ganainy, Henning Schomerus, Liang Feng

Department of Physics Publications

Topological physics provides a robust framework for strategically controlling wave confinement and propagation dynamics. However, current implementations have been restricted to the limited design parameter space defined by passive topological structures. Active systems provide a more general framework where different fundamental symmetry paradigms, such as those arising from non-Hermiticity and nonlinear interaction, can generate a new landscape for topological physics and its applications. Here, we bridge this gap and present an experimental investigation of an active topological photonic system, demonstrating a topological hybrid silicon microlaser array respecting the charge-conjugation symmetry. The created new symmetry features favour the lasing of a ...


Power-Law Scaling Of Extreme Dynamics Near Higher-Order Exceptional Points, Q. Zhong, Demetrios N. Christodoulides, M. Khajavikhan, K. G. Makris, Ramy El-Ganainy Feb 2018

Power-Law Scaling Of Extreme Dynamics Near Higher-Order Exceptional Points, Q. Zhong, Demetrios N. Christodoulides, M. Khajavikhan, K. G. Makris, Ramy El-Ganainy

Department of Physics Publications

We investigate the extreme dynamics of non-Hermitian systems near higher-order exceptional points in photonic networks constructed using the bosonic algebra method. We show that strong power oscillations for certain initial conditions can occur as a result of the peculiar eigenspace geometry and its dimensionality collapse near these singularities. By using complementary numerical and analytical approaches, we show that, in the parity-time (PT) phase near exceptional points, the logarithm of the maximum optical power amplification scales linearly with the order of the exceptional point. We focus in our discussion on photonic systems, but we note that our results apply to other ...


Nonthermal Ice Nucleation Observed At Distorted Contact Lines Of Supercooled Water Drops, Fan Yang, Owen Cruikshank, Weilue He, Alexander Kostinski, Raymond Shaw Feb 2018

Nonthermal Ice Nucleation Observed At Distorted Contact Lines Of Supercooled Water Drops, Fan Yang, Owen Cruikshank, Weilue He, Alexander Kostinski, Raymond Shaw

Department of Physics Publications

Ice nucleation is the crucial step for ice formation in atmospheric clouds and therefore underlies climatologically relevant precipitation and radiative properties. Progress has been made in understanding the roles of temperature, supersaturation, and material properties, but an explanation for the efficient ice nucleation occurring when a particle contacts a supercooled water drop has been elusive for over half a century. Here, we explore ice nucleation initiated at constant temperature and observe that mechanical agitation induces freezing of supercooled water drops at distorted contact lines. Results show that symmetric motion of supercooled water on a vertically oscillating substrate does not freeze ...


Data Supporting The Paper "Influence Of Microphysical Variability On Stochastic Condensation In A Turbulent Laboratory Cloud", N. Desai, K. K. Chandrakar, K. Chang, Will Cantrell, Raymond Shaw Jan 2018

Data Supporting The Paper "Influence Of Microphysical Variability On Stochastic Condensation In A Turbulent Laboratory Cloud", N. Desai, K. K. Chandrakar, K. Chang, Will Cantrell, Raymond Shaw

Department of Physics Publications

No abstract provided.


Global Association Of Aerosol With Flash Density Of Intense Lightning, Orit Altaratz, Beata Kucienska, Alexander Kostinski, Graciela B. Raga, Ilan Koren Nov 2017

Global Association Of Aerosol With Flash Density Of Intense Lightning, Orit Altaratz, Beata Kucienska, Alexander Kostinski, Graciela B. Raga, Ilan Koren

Department of Physics Publications

A global scale study of the association between aerosol loading and lightning production was conducted, using a full year’s data for 2012 (as well as seasonal data) of the cloud-to-ground lightning record from the world wide lightning location network and aerosol optical depth measured by MODIS. 70% of all grid squares examined and 94% of the statistically significant ones had higher flash densities under polluted conditions than the clean ones. This trend is evident for large continental regions in North, Central and South America, Europe, southern Africa and north-east Australia. A detailed examination of the link to the meteorology ...


Robustness And Mode Selectivity In Parity-Time (Pt) Symmetric Lasers, M. H. Teimourpour, M. Khajavikhan, Demetrios N. Christodoulides, Ramy El-Ganainy Sep 2017

Robustness And Mode Selectivity In Parity-Time (Pt) Symmetric Lasers, M. H. Teimourpour, M. Khajavikhan, Demetrios N. Christodoulides, Ramy El-Ganainy

Department of Physics Publications

We investigate two important aspects of PT symmetric photonic molecule lasers, namely the robustness of their single longitudinal mode operation against instabilities triggered by spectral hole burning effects, and the possibility of more versatile mode selectivity. Our results, supported by numerically integrating the nonlinear rate equations and performing linear stability analysis, reveals the following: (1) In principle a second threshold exists after which single mode operation becomes unstable, signaling multimode oscillatory dynamics, (2) For a wide range of design parameters, single mode operation of PT lasers having relatively large free spectral range (FSR) can be robust even at higher gain ...


Cloud Droplets To Drizzle: Contribution Of Transition Drops To Microphysical And Optical Properties Of Marine Stratocumulus Clouds, S Glienke, A. Kostinski, J P. Fugal, R. A. Shaw, S Borrmann, J Stith Aug 2017

Cloud Droplets To Drizzle: Contribution Of Transition Drops To Microphysical And Optical Properties Of Marine Stratocumulus Clouds, S Glienke, A. Kostinski, J P. Fugal, R. A. Shaw, S Borrmann, J Stith

Department of Physics Publications

Aircraft measurements of the ubiquitous marine stratocumulus cloud type, with over 3000 km of in situ data from the Pacific during the Cloud System Evolution in the Trades experiment, show the ability of the Holographic Detector for Clouds (HOLODEC) instrument to smoothly interpolate the small and large droplet data collected with Cloud Droplet Probe and 2DC instruments. The combined, comprehensive instrument suite reveals a surprisingly large contribution in the predrizzle size range of 40–80 μm (transition droplets, or drizzlets), a range typically not measured and assumed to reside in a condensation‐to‐collision minimum between cloud droplet and drizzle ...


Two-Dimensional Electronics And Optoelectronics: Present And Future, Zhixian Zhou, Yoke Khin Yap Jul 2017

Two-Dimensional Electronics And Optoelectronics: Present And Future, Zhixian Zhou, Yoke Khin Yap

Department of Physics Publications

Since the successful isolation of graphene a little over a decade ago, a wide variety of two-dimensional (2D) layered materials have been studied. They cover a broad spectrum of electronic properties, including metals, semimetals, semiconductors, and insulators. Many of these 2D materials have demonstrated promising potential for electronic and optoelectronic applications.


Non-Hermitian Matter-Wave Mixing In Bose-Einstein Condensates: Dissipation-Induced Amplification, S. Wuster, Ramy El-Ganainy Jul 2017

Non-Hermitian Matter-Wave Mixing In Bose-Einstein Condensates: Dissipation-Induced Amplification, S. Wuster, Ramy El-Ganainy

Department of Physics Publications

We investigate the nonlinear scattering dynamics in interacting atomic Bose-Einstein condensates under non-Hermitian dissipative conditions. We show that, by carefully engineering a momentum-dependent atomic loss profile, one can achieve matter-wave amplification through four-wave mixing in a quasi-one-dimensional nearly-free-space setup—a process that is forbidden in the counterpart Hermitian systems due to energy mismatch. Additionally, we show that similar effects lead to rich nonlinear dynamics in higher dimensions. Finally, we propose a physical realization for selectively tailoring the momentum-dependent atomic dissipation. Our strategy is based on a two-step process: (i) exciting atoms to narrow Rydberg or metastable excited states, and (ii ...


Recent Advances In Electronic And Optoelectronic Devices Based On Two-Dimensional Transition Metal Dichalcogenides, Mingxiao Ye, Dongyan Zhang, Yoke Khin Yap Jun 2017

Recent Advances In Electronic And Optoelectronic Devices Based On Two-Dimensional Transition Metal Dichalcogenides, Mingxiao Ye, Dongyan Zhang, Yoke Khin Yap

Department of Physics Publications

Two-dimensional transition metal dichalcogenides (2D TMDCs) offer several attractive features for use in next-generation electronic and optoelectronic devices. Device applications of TMDCs have gained much research interest, and significant advancement has been recorded. In this review, the overall research advancement in electronic and optoelectronic devices based on TMDCs are summarized and discussed. In particular, we focus on evaluating field effect transistors (FETs), photovoltaic cells, light-emitting diodes (LEDs), photodetectors, lasers, and integrated circuits (ICs) using TMDCs.


Terrestrial Glint Seen From Deep Space: Oriented Ice Crystals Detected From The Lagrangian Point, Alexander Marshak, Tamas Varnai, Alexander Kostinski May 2017

Terrestrial Glint Seen From Deep Space: Oriented Ice Crystals Detected From The Lagrangian Point, Alexander Marshak, Tamas Varnai, Alexander Kostinski

Department of Physics Publications

The Deep Space Climate Observatory (DSCOVR) spacecraft resides at the first Lagrangian point about one million miles from Earth. A polychromatic imaging camera onboard delivers nearly hourly observations of the entire sunlit face of the Earth. Many images contain unexpected bright flashes of light over both ocean and land. We construct a yearlong time series of flash latitudes, scattering angles, and oxygen absorption to demonstrate conclusively that the flashes over land are specular reflections off tiny ice platelets floating in the air nearly horizontally. Such deep space detection of tropospheric ice can be used to constrain the likelihood of oriented ...


Topological Tight-Binding Models From Nontrivial Square Roots, J. Arkinstall, M. H. Teimourpour, L. Feng, Ramy El-Ganainy, H. Schomerus Apr 2017

Topological Tight-Binding Models From Nontrivial Square Roots, J. Arkinstall, M. H. Teimourpour, L. Feng, Ramy El-Ganainy, H. Schomerus

Department of Physics Publications

We describe a versatile mechanism that provides tight-binding models with an enriched, topologically nontrivial band structure. The mechanism is algebraic in nature, and leads to tight-binding models that can be interpreted as a nontrivial square root of a parent lattice Hamiltonian—in analogy to the passage from a Klein-Gordon equation to a Dirac equation. In the tight-binding setting, the square-root operation admits to induce spectral symmetries at the expense of broken crystal symmetries. As we illustrate in detail for a simple one-dimensional example, the emergent and inherited spectral symmetries equip the energy gaps with independent topological quantum numbers that control ...