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Jeremy Levy named American Association for Advancement of Science (AAAS) Fellow

  • By Ke Xu
  • 30 November 2018

American Association for Advancement of Science (AAAS) has appointed Jeremy Levy as member of its 2018 lifetime fellowship cohort. AAAS will recognize the award during its annual meeting on February 16, 2019. 

Levy’s research centers around the field of oxide nanoelectronics, quantum computation, quantum transport and nanoscale optics, semiconductor and oxide spintronics, and dynamical phenomena in oxide materials and films. 

Levy will join a list of distinguished scientists including inventor Thomas Edison, astronomer Maria Mitchell and computer scientist Grace Hopper.
 

Single-shot condensation of exciton polaritons and the hole burning effect

  • By Leena Aggarwal
  • 10 September 2018

The single-shot measurements offer a unique opportunity to study fundamental properties of non-equilibrium condensation in the presence of a reservoir. David Snoke and his colleagues have recently reported an insight into spontaneous condensation by imaging long-lifetime exciton polaritons in a high-quality inorganic microcavity in a single-shot optical excitation regime, without averaging over multiple condensate realisations. The results are published in the Journal of Nature Communications. They have demonstrated that how condensation is strongly influenced by an incoherent reservoir and that the reservoir depletion, the so-called spatial hole burning, is critical for the transition to the ground state.

Ultrafast Microscopy of Spin-Momentum Locked Surface Plasmon Polaritons

  • By Leena Aggarwal
  • 27 June 2018

The recently published paper in journal of ACS NANO on Ultrafast Microscopy of Spin-Momentum Locked Surface Plasmon Polaritons is an essential research for designing optical elements to control spin-polarized SPP (surface plasmon polaritons) fields on the nano femto scale. Hrvoje Petek and his colleagues have shown two-photon photoemission electron microscopy images formed by coupling and propagation of longitudinal and transverse components of SPP fields of light. Further, they have also shown the spin-momentum locked SPP wave packets launched with circularly polarized excitation propagate at the same phase and group velocities as for the linearly polarized excitation using time-resolved experiments.

 

 

Large enhancement of response times of a protein conformational switch by computational design

  • By Leena Aggarwal
  • 16 April 2018

Lillian Chong and her colleagues have recently reported, in the Journal of Nature Communications, a computational design strategy in synergistic combination with biophysical experiments to rationally improve the response time of an engineered protein-based Ca2+-sensor in which the switching process occurs via mutually exclusive folding of two alternate frames. This strategy identifies mutations that increase switching rates by as much as 32-fold, achieving response times on the order of fast physiological Ca2+ fluctuations. This computational design strategy is general and may aid in optimizing the kinetics of other protein conformational switches.

Critical heat flux enhancement in pool boiling through increased rewetting on nanopillar array surfaces

  • By Leena Aggarwal
  • 12 April 2018

Boiling is a key heat transfer process for a variety of power generation and thermal management technologies. The enhancement in both the critical heat flux (CHF) and the critical temperature at CHF of the substrate and effectively increase the limit of boiling before the boiling crisis is triggered. By using only nanopillars with a systematic variation in height and well-defined geometrical dimensions, Paul W. Leu and colleagues have established a direct link between the enhancement in capillary force and the boiling performance of a substrate. This provides new insights about design of surface textures not only to amplify the heat flux, but also to achieve an enhancement in the temperature at critical heat flux. These results are published in Scientific Reports.

Size, Shape, and Composition-Dependent Model for Metal Nanoparticle Stability Prediction

  • By Leena Aggarwal
  • 4 April 2018

Giannis Mpourmpakis and his students have proposed a bond-centric (BC) model able to capture cohesive energy trends over a range of monometallic and bimetallic nanoparticles and mixing behavior (excess energy) of nanoalloys, in great agreement with DFT calculations. This model utilizes to calculate the energetics of any nanoparticle morphology and chemical composition, thus significantly accelerating nanoalloys design. This work introduces a simple yet very powerful tool for nanoalloy design that can potentially help elucidate the energetics of alloy MNP genomes.

 

Segregation-induced ordered superstructures

  • By Burcu Ozden
  • 21 March 2018

Michael Widom and his colleagues showed what happens at the grain boundaries of one particular alloy of the metals nickel and bismuth that makes it brittle in their paper published in Science. Using advanced electron microscopes, Widom’s collaborators at Lehigh University scrutinized these microscopic grain boundaries at an atomic level. In a "very heroic experimental program" they discovered that when grains met, the bismuth and nickel atoms realigned into lattices to form layered superstructures at the grain boundaries. These superstructures had previously been thought to exist only rarely in some alloys. Finding it at many different boundaries led the team to conclude that these superstructures are probably much more common than many people had thought. 

Chiral nanocluster with open shell electronic structure and helical face-centered cubic framework

  • By Leena Aggarwal
  • 2 March 2018

Owing to high surface to volume ratios and chemical potential, nanoparticles possess unique optical, electrical, and thermal properties, which constitute the basis of novel applications in sensing, catalysis, nanoelectronics, bio-tagging etc. Despite the great advances in the synthesis, the total structure determination of nanoclusters still remains to be a major challenge. Recently Hyung J. Kim and their colleagues have reported the synthesis and crystal structure of a nanocluster composed of 23 silver atoms capped by 8 phosphine and 18 phenylethanethiolate ligands in the journal of Nature Communications.

Engineering of spin canting across core/shell Fe3O4/MnxFe3−xO4 nanoparticle

  • By Leena Aggarwal
  • 27 February 2018

In the recently published paper in Scientific Reports, Sara A. Majetich and their colleagues have demonstrated the engineering of spin canting across a Magnetic nanoparticles (MNP) via the Dzyaloshinskii-Moriya interaction (DMI). In this paper, they have shown that strong DMI can lead to magnetic frustration within the shell and cause canting of the net particle moment. These results have illuminated how core/shell nanoparticle systems can be engineered for spin canting across the whole of the particle, rather than solely at the surface.

 

Building Smarter Windows

  • By Burcu Ozden
  • 21 February 2018

Paul Leu and his student Sajad Haghanifar, a PhD candidate, developed a new type of glass 1,000 times thinner than a human hair which could potentially used as solar panels for smart windows.

While the solar energy industry is expanding — at an average annual rate of 68 percent from 2006 to 2016, according to the Solar Energy Industries Association — solar panels and solar cells still have an efficiency issue.

Paul Leu said, " Any light that is not being absorbed by your solar cell is decreasing the efficiency of your solar panel," and added “Anything you can do to increase your efficiency is good.”

Leu said that the new glass they developed has advantagous of scattering light energy at different angles, giving the light that does bounce off a better chance to be trapped and converted into useable energy

He added, “With these nanostructures, you can get the reflection rate close to zero.” 

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