Month: May 2017

The first 3-D quantum liquid crystals may have applications in quantum computing, report scientists. Liquid crystals fall somewhere in between a liquid and a solid: they are made up of molecules that flow around freely as if they were a liquid but are all oriented in the same direction, as in a solid. Liquid crystals can be found in nature, such as in biological cell membranes. Alternatively, they can be made artificially — such as those found in the liquid crystal displays commonly used in watches, smartphones, televisions, and other items that have display screens.

These images show light patterns generated by a rhenium-based crystal using a laser method called optical second-harmonic rotational anisotropy. At left, the pattern comes from the atomic lattice of the crystal. At right, the crystal has become a 3-D quantum liquid crystal, showing a drastic departure from the pattern due to the atomic lattice alone.

In a “quantum” liquid crystal, electrons behave like the molecules in classical liquid crystals. That is, the electrons move around freely yet have a preferred direction of flow. The first-ever quantum liquid crystal was discovered in 1999 by Caltech’s Jim Eisenstein, the Frank J. Roshek Professor of Physics and Applied Physics. Eisenstein’s quantum liquid crystal was two-dimensional, meaning that it was confined to a single plane inside the host material — an artificially grown gallium-arsenide-based metal. Such 2-D quantum liquid crystals have since been found in several more materials including high-temperature superconductors — materials that conduct electricity with zero resistance at around -150 degrees Celsius, which is warmer than operating temperatures for traditional superconductors.

Source (California Institute of Technology. “New quantum liquid crystals may play role in future of computers: New state of matter may have applications in ultrafast quantum computers.” ScienceDaily. ScienceDaily, 20 April 2017.)

Original paper: Harter, J.W., Zhao, Z.Y., Yan, J.Q., Mandrus, D.G. and Hsieh, D., 2017. A parity-breaking electronic nematic phase transition in the spin-orbit coupled metal Cd2Re2O7. Science, 356(6335), pp.295-299.

A chemistry professor has just found a way to trigger the process of photosynthesis in a synthetic material, turning greenhouse gases into clean air and producing energy all at the same time. The process has great potential for creating a technology that could significantly reduce greenhouse gases linked to climate change, while also creating a clean way to produce energy.

Uribe-Romo and his team of students created a way to trigger a chemical reaction in a synthetic material called metal-organic frameworks (MOF) that breaks down carbon dioxide into harmless organic materials. Think of it as an artificial photosynthesis process similar to the way plants convert carbon dioxide (CO₂) and sunlight into food. But instead of producing food, Uribe-Romo’s method produces solar fuel. Uribe-Romo used titanium, a common nontoxic metal, and added organic molecules that act as light-harvesting antennae to see if that configuration would work. The light harvesting antenna molecules, called N-alkyl-2-aminoterephthalates, can be designed to absorb specific colors of light when incorporated in the MOF. In this case he synchronized it for the color blue.

Source (Zenaida Gonzalez Kotala, “UCF Professor Invents Way to Trigger Artificial Photosynthesis to Clean Air, Produce Energy”, UCF Today, 24.04.2017)