Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Quantum 'kisses 'change the color of space

08.11.2012
Published in Nature, observed for the first time with optical methods the quantum regime in the interaction between nano-sized spheres of gold

Researchers from the Donostia International Physics Center (DIPC) and the Materials Physics Center in Donostia-San Sebastián (CFM) have observed for the first time, with optical methods, the quantum regime in the interaction between nano-sized spheres of gold.


The image shows, in an artistic manner, the change in color when a quantum tunnel effect is produced in a subnanometric gap.

Credit: Picture courtesy of Cambridge University

This quantum regime has been identified thanks to the change of colour of the gap or empty space between these particles when these are at distances of less than one nanometre. This work, published in Nature journal, enables literally "seeing" a quantum kiss between nanoparticles.

The gap generated between two opposing nanospheres of gold can change its colour when the distance between them is less than one nanometre, according to recent research co-directed by researchers from the DIPC and the CFM (a joint center between the CSIC [Spanish Scientific Research Council] and the UPV/EHU [the University of the Basque Country]), both based in the Basque City of Donostia-San Sebastián, and in collaboration with researchers from the Universities of Cambridge and Paris-Sud.

This work published in Nature, confirmed that electrons accumulated on the gold walls around the illuminated gap between the spheres can "jump" from one to the other, thanks to the tunnel effect, thus reducing the accumulated charge on the surface of each of these spheres and modify the colour of the gap from red to blue (blueshifting).

This work enables literally "seeing" the effects of quantum mechanics and shows how light interacts with matter at subnanometre sizes. The change in colour of the gap is a "chromatic fingerprint" that identifies the initiation of a quantum regime therein - an effect that had been predicted by the theoretical team of Dr. Aizpurua, the lead researcher in Donostia, and now fully identified as a result of this research. To this end, highly sophisticated experiments have been combined with very advanced theories.

When two metallic spheres with a sufficiently small separation between them are illuminated with white light, this gap acquires colour thanks to the interaction of the electrons on the surface of the spheres with light. The beam of light 'pushes' the electrons and makes them oscillate, which gives a red colour to the gap. As the spheres get closer, the electron charge increases and this red colour intensifies. When the distance between both is reduced to under 0.35 nanometres, this accumulation of charge can be seen to drop, due to the tunnel effect, and thanks to which the electrons can jump from one ball to another without the spheres coming into contact with each other. Just as the quantum theory developed by the research teams in Donostia and Paris predicted, it is possible to identify this quantum electronic leap, given that, as the accumulated charge drops, the red colour of the gap changes to blue.

Experimental team leader and University of Cambridge researcher, Professor Jeremy Baumberg compares this reduction in charge with the tension released from a kiss "we think of this like the tension building up between a romantic couple. As their faces get closer the tension mounts, and only a kiss discharges this energy". In this case, however, the gold nanospheres approaching each other generate a virtual kiss, as they never actually touch, releasing the charge on their surfaces and changing the colour of the gap between them. As Professor Baumberg says, "it is practically like kissing, without the lips actually touching".

The experimental team at Cambridge explained: "aligning two gold nano-particles is like closing your eyes and trying to hold two needles with the fingers of either hand so that the points of each needle touch. Achieving this has meant years of hard work".

Javier Aizpurua commented that, in order to predict the colour changes now confirmed with this experiment, "the fusion of the quantum vision with the classical vision of the world" was necessary. "The modelling of so many electrons oscillating within the gold particles in response to a beam of light could not be described with existing theories", assured the CSIC and DIPC researcher.

This new result establishes a fundamental quantum limit for the minimum dimensions within which we can trap light. Moreover, this reinterpretation of the interaction between light and matter at a sub-nanometric scale could provide new ways of describing and measuring the atomic-scale world and open doors to new strategies for the manufacture of even smaller optoelectric technological devices and access new limits of resolution in photochemistry.

This research was funded by the Basque Government through its Science Agency, Ikerbasque, and the ETORTEK Nanoscience and Nanotechnology project, as well as by a European Union initiative through the Eranet CUBiHOLE project which originally brought together the teams involved in this research. Part of this work was developed during the time spent by Professor Baumberg as an Ikerbasque Visiting Professor at the DIPC.

Aitziber Lasa | EurekAlert!
Further information:
http://www.elhuyar.com

More articles from Physics and Astronomy:

nachricht Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie

nachricht Seeing the quantum future... literally
16.01.2017 | University of Sydney

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>