Scientists Create Crystal M bius Strip

Scientific American ^ | FR Post 5-29-02 | Editorial Staff

[vannrox]

Scientists Create Crystal Möbius Strip

A signature of arts and crafts sessions, the Möbius strip--a seemingly endless ribbon with only one side and one edge that can be made from construction paper and sticky tape--has been given a new look. According to a report published today in the journal Nature, scientists have succeeded in growing crystals in the form of Möbius structures.


A piece of ribbon or paper can be twisted and turned easily, so a regular Möbius strip itself is no great feat of engineering. Crystals, in contrast, contain an inherently rigid structure. To manufacture their miniature Möbius strips, Satoshi Tanda of Hokkaido University in Japan and his colleagues placed a mixture of selenium (Se) and niobium (Nb) powder in a quartz tube and heated it to temperatures greater than 700 degrees Celsius. Under these conditions, Se changes among vapor, mist and liquid phases. The tiny drops of liquid selenium acted as spools on which the strips formed (see image). As the crystals of NbSe3 grew, they wrapped around the droplet and the two ends met, making a seamless ring the diameter of a human hair. By changing the growing conditions, the researchers coaxed the crystals into twisting either once, resulting in a Möbius strip, or twice, which created a "figure-of-eight" crystal strip.


Exactly what these mini Möbius strips could be used for is unclear. But the scientists suggest that strips of different sizes could be manufactured by varying the size of the liquid drops, and they have already applied their technique to a number of other compounds. The authors propose that these strangely shaped crystals could aid studies of the quantum mechanical effects of surface features. --Sarah Graham

[vannrox]

Cool...

[callisto]

Definitely cool, as are most all of your posts. I seem to following you around on the forum this afternoon, unintentionally of course.

[boris]

Lemme know when they grow a Klein bottle.

I bought mine at Acme Klein Bottles

[RonDog]

From http://exp-ap.eng.hokudai.ac.jp/:

"We have found new types of transition metal chalcogenide crystals (NbSe₃, TaS₃, TaSe₃) which have the shapes of a ring, a disk, or a Mobius strip of 10-100 micrometers size.

Aside from their peculiarity in the outer shapes, it is found that the lattice spaces of these striking crystal forms have topologies of twisted loops themselves. In this sense the matters are distinctive compared to ordinary rectilinear crystals, whose topology is just trivial.

In fact, this new group of crystals is a physical realization of the "ribbon-knots" group in the field of topology, which deals with geometries of two-faced, closed loops. Hence the name "topological matters".

We researchers of solid state physics are interested in quantum mechanical behavior of electrons in such a twisted, closed loop system. However, approaches from various research fields, e.g. chemistry in their formation process, crystallographic view on their structural distortion, or mathematical determination of the optimal surfaces for a topology etc. will be granted."

[vannrox]

WOW. Big Bump.