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Pick a Material, Not just Any Material, for a Metamaterial

Designing the building blocks of artificially engineered materials, known as metamaterials, just got easier. Metamaterials are built from small engineered structures that, in some ways, mimic the role of atoms, and can manipulate light in ways not seen in nature. The conducting materials used to make them are central to their efficiency. Energy is lost by conversion of light to heat in the metallic components and the support materials. Gold and silver are known to be relatively good building block materials and now we have a way to predict which other materials could work even better.

Single File Line, Please!

Researchers can now analyze how reactions proceed inside porous nanoparticles where the molecules are in such narrow channels that they cannot pass each other. Catalysis within these confined conditions is significantly impacted by restricted transport. Typical pore diameters are in the range of 2 - 10 nm, and with catalyst molecules attached inside them, the pore diameter can be reduced below 2 nm.

Quantum Computing Hurdle Cleared

Researchers have overcome a fundamental obstacle to realizing the full potential of quantum computing.They developed a method to protect quantum information while simultaneously performing calculations. When a quantum bit (qubit) interacts with the environment its quantum information is quickly destroyed. Until now, methods to decouple individual qubits from the environment isolated the qubits from each other so they could not exchange information. The scientists devised a scheme that seamlessly integrates decoupling from the environment into the quantum computation process.

Manipulating Light with a Single Layer of Carbon

Researchers have shown that it may be possible to make lasers using single-layer sheets of carbon atoms — the novel material known as graphene. Lasers are made from materials that can absorb ordinary light and then emit photons that have matching waves to provide high intensity.To generate laser power, a material must first undergo a population inversion where an excess of electrons is excited.

Encouraging Superconductivity with Elemental Substitutions

Advanced techniques have revealed what happens to the magnetism in an iron-arsenide superconductor when some of the iron atoms are replaced by iridium.Substituting some iron atoms by transition metals (TM) such as cobalt, nickel, platinum and iridium suppresses the magnetic order of the non-superconducting parent phases of the iron pnictides, which promotes superconductivity.  The way this happens remains one of the most intriguing puzzles in the field.

Follow the Light

Just like watching boats in the night, seeing movement at the nanoscale is easier when the object you are watching has a beacon.Dynamic three-dimensional tracking with high precision is possible with nanoscale light emitting particles known as quantum dots at better resolution than 10 nanometers in the vertical direction.  This opens up the possibility for understanding three dimensional movement in nanoscale structures and biological systems.  Th

3D Tracking at the Nanoscale

A new theory shows that reactivity at catalytic sites inside narrow pores is controlled by how molecules move at the pore openings. Like cars approaching a single lane tunnel from which other cars are emerging, the movement of molecules depends on their distance into the pore; near the ends of the pores, exchange is rapid compared to further into the pores.

Finding Order Amid the Chaos

Glass is often described as being like a liquid, with randomly arranged atoms.New insights are emerging that show some distinct levels of order within the structure of glasses. Our rapidly evolving understanding arises from new structural information made possible because of advanced light sources like the U.S. Department of Energy’s Advanced Photon Source. The new theory fits experimental data better than the widely accepted model based on icosahedral-like clusters. The new model shows many crystal-like polyhedra as well as clustering of polyhedra — features not seen in previous models.

Warning: Single Lane Tunnel Ahead

A new theory shows that reactivity at catalytic sites inside narrow pores is controlled by how molecules move at the pore openings. Like cars approaching a single lane tunnel from which other cars are emerging, the movement of molecules depends on their distance into the pore; near the ends of the pores, exchange is rapid compared to further into the pores.

What Makes a High-temperature Superconductor a Superconductor?

Researchers may have discovered the key to high temperature superconductivity — quantum criticality. A quantum critical point occurs where a material undergoes a continuous transformation at absolute zero. For superconducting cuprates and iron-arsenides, the curve of the superconducting transition temperature, Tc, versus doping (or pressure) is dome shaped. It wasn’t clear until now if superconductivity prevents a quantum critical point or if quantum critical behavior is hidden beneath the dome.

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