ESF’s EUROCORES Program EuroQUAM presents itself at ESOF
Many
of us have been fascinated by the concept of absolute zero, the
temperature at which everything comes to a complete stop. But physics
tells us otherwise: absolute zero cannot be reached but only
approached, and the closer you get, the more interesting phenomena you
find!
Three outstanding scientists from ESF’s EUROCORES
Programme EuroQUAM gave insight into this ‘cool’ matter at the event
"The Amazing Quantum World of Ultra Cold Matter", held at this year’s
ESOF (Euroscience Open Forum) in Barcelona. It was co-organised by the
European Science Foundation (ESF) and The Institute of Photonic
Sciences (ICFO) within the collaborative research programme "Cold
Quantum Matter" (EuroQUAM).
Maciej Lewenstein leads the
quantum optics theory group at ICFO and is a Humboldt Research Prize
Awardee. Introducing the basics of quantum mechanics, he explained
without mathematics why laser light cools atoms and told the audience
about recent developments in atomic, molecular and optical physics and
quantum optics, toward reaching temperatures close to absolute zero. "I
expect major developments in fields like quantum information", said
Lewenstein. He argued that while in classical physics absolute zero is
in certain sense "boring", in the quantum world new, fascinating states
of matter such as Bose-Einstein condensates arise at ultralow
temperatures. Moreover, he elaborated on the tremendous advances in
physics that have made such experiments possible, and which led to
Nobel prizes in physics in 1997 and 2001. "Concerning Nobel Prizes in
this area, it’s only a question of who’s next" predicted Lewenstein.
Christophe
Salomon is Head of the cold Fermi gas group at Ecole Normale
Supérieure, France and Principal Investigator for the ACES/PHARAO Space
Clock Mission. He has received the "Three Physicists" prize (FR), the
Mergier-Bourdeix Grand Prize of the French Academy of Sciences, the
European Time and Frequency Prize, and the Philip-Morris Prize.
In
his talk "Precision Time with Cold Atoms" he described an important
application of cold atoms, the realization of ultra precise clocks.
Using atomic fountains and microwave radiation, the SI unit of time,
the second, is realised with an error of less than one second over 100
million years. Clocks operating in the optical domain show even better
performances and cycles of light can now be easily counted with a
femtosecond laser. "In a few years clocks will be able to monitor local
changes of the Earth gravitational potential by using relativity, which
might help us forecast tsunamis, earthquakes, or global climate
warming", said Salomon.
The third speaker, Christopher Foot,
Professor of Physics at Oxford University, elucidated "The
extraordinary behaviour of quantum systems". Small particles such as
atoms and electrons behave in strange ways that often seem very weird
when compared to our everyday experience of large ‘ordinary’ objects
such as a tennis ball or football. For these very small objects the
effects of quantum mechanics are manifested in striking ways, which
Foot outlined.
A single quantum object can exist in two
places at once – "It is in a state of indecision" said Foot.
Additionally, there is a second property of quantum systems of two or
more particles that is truly difficult to understand, known as
entanglement. Indeed Einstein pointed out that this so-called "spooky
action at a distance" is so bizarre that he thought there must be
something wrong. Experiments have shown, however, that the quantum
world really behaves in this peculiar way. "By understanding it we can
do new things such as build quantum computers that, in the future,
could store and process far more information than ‘ordinary computers’
and may outperform them in certain applications, e.g. cracking the
encryption commonly used to transmit information electronically"
explained Foot.
With current technology, quantum systems of
many atoms at temperatures less than one millionth of a degree above
absolute zero can be made. These systems can be controlled in such a
way that they act like small quantum calculating machines, or ‘quantum
simulators’, with which the quantum properties of a wide range of other
interesting physical systems can be studied. Foot also gave an example
of this type of experiment currently carried out in the EuroQUAM
Programme, where laser beams are used to form ‘optical lattices’ that
resemble crystals.
Spanish Anchorman and former Minister of
European Relations in the Spanish Government Eduardo Punset moderated
the event, and Jürgen Eschner, an experimentalist and group leader from
ICFO, was the main organizer of this activity of EuroQUAM. "I think our
biggest challenge in the coming years is to bring together knowledge
and entertainment, and the speakers captivated the public here in
Barcelona" said Punset. ESOF marked a unique opportunity for EuroQUAM
to go public with its research and make cold quantum matter more
graspable. "We have clearly conveyed the fascination that the EuroQUAM
scientists have for the exciting fundamental phenomena and
technological opportunities of ultra-cold matter" concluded Eschner.
For further information on EuroQUAM, please go to www.esf.org/euroquam.
For further information on EUROCORES, please go to www.esf.org/eurocores.
For further information on ICFO, please go to www.icfo.es.
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