It's Quantum Mechanics... Or Something
by Eric Hall
August 18, 2014
Scientists get things wrong very often. I, for one, am thankful they do. Being wrong is an opportunity to learn new and interesting things about the world. Or it might simply mean we need to do more work in order to see how our hypothesis was wrong. Giving scientists an opportunity to be wrong and the opportunity to simply explore is one of the best things we can do to make better and more useful technology. And in the last couple weeks we've gotten to see hints as to what this powerful research can bring about.
First, I want to explain the humor of my title. Those of you familiar with scientific skepticism understand that there are many pseudoscience peddlers that try to use quantum mechanics as a way to explain their bogus claims. The recent news I will briefly explain next actually does involve quantum mechanics. Even for physicists, it is not an easy concept. I will use an explanation that involves quantum mechanics, but at a very basic level. Please forgive me if you have some background in the subject and I over-simplify it, but I want to make this accessible for a wide range of readers.
The first story is an international team has been studying the properties of various metal oxides, specifically transition metals. Transition metals are the ones found in the center of the periodic table. As the authors state:
Transition metal oxides have emerged as one of the foci for condensed matter physics research due to the multitude of structural, electronic and magnetic phenomena they exhibit.What they found when they built these metal oxide crystals and looked at them using high-resolution scanning tunneling microscopy was the pattern on the top was distorted, but in a regular zig-zag pattern. This was unexpected at first, but after running calculations they found it made sense these patterns would emerge.
The basic idea from quantum mechanics at work here is that electrons eventually end up at the lowest possible energy state, at least when energy is not being added from an outside source. The only way for the electrons of these oxygen atoms to be at their lowest state was to organize themselves in these patterns, something confirmed by the modeling done after observing the patterns. As Zheng Gai, one of the study's authors explains:
The oxygen totally changes the surface energy. Once you introduce oxygen, the electrons don't like to form a straight line; they zigzag to get to a lower energy state. This distortion is a very common concept in bulk materials, but nobody has been able to show this effect on the surface before.The researchers are very excited because they found that manipulating one of the atoms caused the others to shift as well. This gives these materials great potential for use in sensors and other electronic devices.
The authors of this paper have been pretty prolific. As the phys.org article points out, this is the seventh publication by the group in four years, which have appeared in some of the most respected journals in the scientific world, such as Science and Nature. This is fantastic and complex work. It has been made possible because of investment in science by the Oak Ridge National Laboratory through the Department of Energy's Office of Science.
Another study regarding metal oxides examined the properties of magnetite films when formed high in the atmosphere without the same concentrations of oxygen usually present during the films' facture at ground level. While the researchers found that this lack of oxygen changed the conductive properties of the bulk (inner) material, they found the surface was remarkably consistent in its properties throughout a wide range of conditions. While one could speculate on the usefulness of such properties, lead author Paul Snijders commented on what this means in the short term:
I always say that in basic science we are discovering the alphabet. How these letters will be designed into a useful technological book is hard to predict.That's a pretty large set of letters, again coming out of ORNL.
So what's the value if we don't see any immediate usefulness? There are some great aspects in having a wider variety of metals from which to make sensors, electronics, and batteries. Some metals are easier to mine and recover due to their abundance and their natural state. They require less energy input to both mine and refine, and have less waste by-product. This could make electronics cheaper and put less stress on the environment. It could also make them easier to recycle.
Another aspect is transition metal oxides are where superconductors are found. Studying the properties could lead to a better understanding of what makes something turn into a superconductor, and possibly find higher temperature superconductors which could lead to a huge energy savings.
Electronics in general could become more efficient. As we look to extend the life of batteries and yet increase the usefulness of the electronics we carry with us, this could lead to conveniences both in daily life and for various work applications. By being able to reduce the size of sensors, we could carry more sensors with us, allowing us to customize how much data we want to gather to suit our own needs. This extends to things like medical condition monitoring, environmental monitoring, and many other uses.
Whenever someone asks me why science is so important, it is hard to answer simply. Science has brought about extended lifespans, added convenience, added safety, added comfort, and many other things we might not even think about. It also continues to both satisfy our curiosity while spawning new, more curious inquiries about the Universe. Sometimes, we just don't know how a discovery might be important to our future. But as long as we keep exploring, we will find out soon enough.
by Eric Hall
@Skeptoid Media, a 501(c)(3) nonprofit