Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Physicists investigate the formation of defects during phase transitions in crystals of ions

12.08.2013
Recent research findings are relevant to a model of matter structure formation tiny fractions of a second after the Big Bang

Research groups at Johannes Gutenberg University Mainz (JGU) and the Physical-Technical Federal Institute (PTB) in Braunschweig, working in collaboration with scientists at the University of Ulm and The Hebrew University of Jerusalem, have been investigating the formation of defects occurring when a Coulomb crystal of ions is driven through a second-order phase transition.

For this purpose, they compressed one-dimensional linear chains of ions at high speeds to form a two-dimensional zigzag structure with a form similar to that of an accordion. This process can lead to the generation of defects in the resultant crystal structure. The probability of such defects forming is determined by the speed of the phase transition. The Kibble-Zurek mechanism, which describes the formation of such defects, is universal as it plays an important role in many physical systems. Among other things, this mechanism is the basis of one theory of how matter was created 10 to the power of minus 30 seconds after the Big Bang. The experiments undertaken in Mainz investigated and analyzed this effect with a hitherto unrivalled precision.

The Mainz research team from the Quantum, Atomic, and Neutron Physics (QUANTUM) work group of the Institute of Physics at Mainz University trapped 16 ions in a Paul trap. In this form of trap, ions are confined to a very small space with the aid of electric fields where they arrange themselves in a sequence like pearls in a necklace. The next step is to drastically reduce the space in which the ions are confined so that the ion chain is compressed and becomes folded to form a zigzag structure. However, the ions can assume a particular zigzag pattern or its mirror-inverted version. If one half of the ion chain takes on a different structure to that of the other half of the ion chain, the two patterns that are the opposite of each other will meet in the middle. Since the two different patterns cannot join perfectly, there will be a defect in the crystal structure right at this point.

Due to the form of the trapping potential, the phase transition first occurs in the center of the ion chain and is then transmitted from the center to the ends of the crystal. If the rate of this transmission is faster than the speed of the exchange of information between two neighboring ions, one of these ions will not be able to orientate itself on the basis of its neighbor's structure and will arrange itself randomly. This is why the probability of such defects occurring is significantly determined by the rate at which the phase transition occurs. The speed can be precisely controlled and varied in ion traps, which allowed the Mainz and Braunschweig researchers to determine the rate at which defects occurred relative to phase transition speed. The experimental findings confirm the hypothetical assumptions on which the Kibble-Zurek mechanism is based at a 2 percent level of significance.

Publications:
S. Ulm, J. Roßnagel, G. Jacob, C. Degünther, S.T. Dawkins, U.G. Poschinger, R. Nigmatullin, A. Retzker, M.B. Plenio, F. Schmidt-Kaler, K. Singer¬¬¬
Observation of the Kibble–Zurek scaling law for defect formation in ion crystals
Nature Communications 4, 2290 (2013)
http://www.nature.com/ncomms/2013/130807/ncomms3290/full/ncomms3290.html
[arXiv:1302.5343]
K. Pyka, J. Keller, H. L. Partner, R. Nigmatullin, T. Burgermeister, D.-M. Meier, K. Kuhlmann, A. Retzker, M.B. Plenio, W.H. Zurek, A. del Campo, T.E. Mehlstäubler
Topological defect formation and spontaneous symmetry breaking in ion Coulomb crystals
Nature Communications 4, 2291 (2013)
http://www.nature.com/ncomms/2013/130807/ncomms3291/full/ncomms3291.html
[arXiv:1211.7005]
Image:
www.uni-mainz.de/bilder_presse/08_physik_kibble-zurek-mechanismus.jpg
Diagram of the ion trap employed. The ions are held in place by the electrical fields between the gold-plated electrodes. The image of the ionic crystal with defect has been massively enlarged.

image/©: QUANTUM, JGU

Related links:
http://www.quantenbit.de – "Cold Ions and Experimental Quantum Information" work group
http://www.quantum.physik.uni-mainz.de/index_ENG.php – QUANTUM work group
http://www.quantummetrology.de – Center for Quantum Engineering and Space-Time Research
Further information:
Dipl.-Phys. Stefan Ulm
QUANTUM work group
Institute of Physics
Johannes Gutenberg University Mainz (JGU)
D 55099 Mainz, GERMANY
phone +49 6131 39-23671
fax +49 6131 39-25179
e-mail: ulmst@uni-mainz.de

Petra Giegerich | idw
Further information:
http://www.quantenbit.de/
http://www.uni-mainz.de/presse/16629_ENG_HTML.php

More articles from Physics and Astronomy:

nachricht NASA's SDO sees partial eclipse in space
29.05.2017 | NASA/Goddard Space Flight Center

nachricht Strathclyde-led research develops world's highest gain high-power laser amplifier
29.05.2017 | University of Strathclyde

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: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>