Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


PTB produces first Bose-Einstein condensate with calcium atoms

The physicist and Nobel Prize winner Wolfgang Ketterle once described it as an "identity crisis" of the atoms: If atoms are caught in a trap and cooled to a temperature close to the absolute zero point, they condense – similar to vapour to water – and take on an all new condition: They become indistinguishable.

This collective condition is called - named for its intellectual fathers - Bose-Einstein condensate. Physicists at the Physikalisch-Technische Bundesanstalt (PTB) have now succeeded for the first time worldwide in producing a Bose-Einstein condensate from the alkaline earth element calcium.

Like a giant wave in the midst of a sea of gaseous calcium atoms, the Bose-Einstein condensate soars. It is composed of approx. 20 000 atoms which are normally not visible to the human eye. However the waves which describe the atoms quantum mechanically, all oscillate synchronously in the condensate and accumulate to form a dense giant wave. In this way, the microscopic pile-up of atoms suddenly becomes macroscopic and therefore visible. Credit: PTB

The use of alkaline earth atoms creates new potential for precision measurements, for example for the determination of gravitational fields. Because as opposed to previous Bose-Einstein condensates from alkali atoms, alkaline earth metals react one million times more responsively to the wavelength at optical excitations – a fact which can be used for super exact measurements. Theresults have now been published in Physical Review Letters.

The quantum mechanical background

Atoms in gases at room temperature behave like a wild bunch: They fly pell-mell at different speeds, collide with one another, and are then hurled again in another direction. However at extremely low temperatures close to the absolute zero point at zero Kelvin (–273.15 degrees Celsius) they nearly come to a standstill. At this point, the laws of quantum mechanics come into effect; these cannot be observed in everyday life and have an unsettling effect on many a non-physicist. The idea of atoms as small spheres does not work any longer. In fact, atoms can now only be described quantum mechanically by waves. Like water waves they can overlap each other. In the case of a Bose-Einstein condensate, the wave functions of up to one million atoms are so synchronised that they pile up to form a giant wave. These formations can grow to one millimeter in size and they can then be photographed. The microcosm presents itself macroscopically – it becomes visible for the observer. In the past few years, such Bose-Einstein condensates have been used for diverse investigations on the fundamentals of quantum mechanics, as a model system for solids or in quantum information.

Potential applications

The wave patterns of excited Bose-Einstein condensates are very responsive to their environment. Thus, by investigating these patterns it is possible to produce highly responsive interferometric sensors, e.g. for magnetic fields but also for gravitation. For the manipulation und excitation of condensates light is used. All Bose-Einstein condensates produced so far worldwide have a common disadvantage: Their broad optical transitions do not allow any precision excitations. In the case of Bose-Einstein condensates from alkaline earth atoms (e.g. calcium and strontium, both of which are being investigated at PTB as to their suitability as optical clocks) their super-narrow optical transitions offer novel potential for precision investigations. Conceivable is their use on satellites, e.g. by geophysicists, who study the deformation of the Earth and thus the change in gravitation.


At PTB it was possible for the first time worldwide to produce a Bose-Einstein condensate from alkaline earth atoms. To this end, 2·106 calcium atoms precooled in a magneto-optical trap were loaded at a temperature of 20µK into optical forceps. Due to the weakening of the holding force hot atoms vaporize, whereby the remaining atoms are cooled. At a temperature of typically 200 nK the critical temperature is reached with 105 atoms. Of these, approx. 2·104 atoms can be cooled to form a pure condensate.

Imke Frischmuth | alfa
Further information:

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

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: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>