An international investigation involving the participation of the Consejo Superior de Investigaciones Científicas (CSIC) has reproduced the experiment of Thomas Young in a molecule of hydrogen, the smallest molecular system that exists. In 1803 the English scientist tested a pattern of interferences in light from a distant source, on passing through a “double slit” and thus being refracted.
This finding confirmed the theory that light had wave motion properties. The authors of this current research, which appears in the latest issue of the journal Science, uses electrons instead of light and the nuclei of the hydrogen molecule as emitting slits.
CSIC researcher Ricardo Díez, Vicedirector of the Centre for Materials Physics (a mixed body of the CSIC and the University of the Basque Country in Donostia-San Sebastián and co-author of the article, explains their experiment: “These interference patterns are the same as those produced, on a large scale, when sunlight passes through Persian blinds, throwing shadow patterns and, as it were, games, on the walls. This phenomenon is due to the fact that (light) particles, as with electrons, can also have wave motion behaviour”.At much smaller sizes, atomic planes can create interferences in the transmission of X rays, thus providing information about the internal structure of materials. This is the fundamental basis of the experimental techniques such as X ray diffraction, thanks to which the DNA double helix structure was discovered. Ricardo Díez explains, “The Laws that predict, for example, the trajectory of a car at a certain speed are not those that govern the behaviour of atomic-sized particles. On a nanometric scale sizes are measured in units a thousand million times smaller than a metre, and the behaviour of objects at this scale can prove to be surprising, almost magical even!”
The researchers reproduced Young’s experiment in the smallest system existing - a molecule of hydrogen -, which consists of two protons and two electrons. The research team used light generated by the large synchrotron accelerator at the Lawrence Berkeley National Laboratory (USA), to extract the two electrons from the molecule of hydrogen. The two protons carry out the role of the two electron-emitting apertures, separated by an extremely small distance – ten thousand millionths of a metre. On its journey to the detector, where they are collected, each one of the electrons shows an interference pattern that suggests wave nature rather than particle motion, and as if emission had taken place from the two points at the same time.
The interference pattern of each one of the two electrons extracted from the molecule is conditioned by the presence and the velocity of the other: the greater the difference in their speeds, the less the interaction between them and the more visible the interference patterns. Under these conditions, the system is more of a quantum nature. “The analysis of the patterns as a function of velocity enables the investigation of the subtle mechanisms of the transition between classical physics and quantum physics. It is necessary to understand the quantum relationship between a small number of electrons, such as those of hydrogen, as it is the basis of concepts as sophisticated as quantum cryptography or of the future development of quantum computation”, concluded the CSIC researcher.
The study was led by University of Frankfurt researcher Reinhard Dörner and involved, moreover, the participation of German North American and Russian scientists.
Garazi Andonegi | alfa
New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center
Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research