PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Shaken, not stirred: Control over complex systems consisting of many quantum particles

At TU Vienna, a new method was developed to utilize quantum mechanical vibrations for high precision measurements; The well-known concept of the Ramsey interferometer is applied to a complex multi particle system consisting of hundreds of atoms

Shaken, not stirred: Control over complex systems consisting of many quantum particles
2014-06-04
(Press-News.org) This news release is available in German.

Sometimes quantum particles behave like waves. This phenomenon is often used for high precision measurements, for instance in atomic clocks. Usually, only the wave properties of single particles play a role, but now researchers at the Vienna Center for Quantum Science and Technology, Vienna University of Technology have succeeded in quantum mechanically controlling hundreds of Rubidium atoms of an ultracold Bose-Einstein-condensate by shaking it in just the right way. Now, not only internal states of atoms can be used for interferometric measurements, but also the collective motional state of all particles.

Superpositions of Different States

According to quantum theory, some physical quantities can only have certain discrete values. If, for instance, the energy of an electron inside an atom is measured, it is always found in special energy states – other energy values are just not allowed. It is similar with the motion of particles, if they are confined to small spaces.

"We catch hundreds of Rubidium atoms in a magnetic trap and cool them so that they form an ultracold Bose-Einstein condensate", says Professor Jörg Schmiedmayer from the Institute for Atomic and Subatomic Physics at the Vienna University of Technology. "This Bose-Einstein-condensate moves as a gigantic matter wave." The laws of quantum physics, however, do not permit every kind of motion, but only a certain set of possible motion waves.

Different Wave States

"It is a bit like blowing a flute", says Sandrine van Frank. "When you blow it, a sound wave is created. If you blow it harder, you can produce a high-pitched overtone." In quantum physics, however, different states can be excited at the same time. With a precisely tailored electromagnetic pulse, developed in collaboration with Prof. Tommaso Calarco of the Institute for Quantum Information at the Univ. Ulm, the Bose-Einstein condensate can be shaken, so that it does not only occupy one of the possible motion states, but two at the same time.

Such a superposition of states is something quite normal in quantum physics. The amazing thing is that a system with hundreds of atoms and many degrees of freedom – in quantum terms something incredibly huge – can be prepared in such a superposition state. Usually, quantum superpositions are extremely fragile. The larger the object, the easier it is to destroy the quantum properties of a superposition of allowed quantum states – a phenomenon called "decoherence". Today, decoherence is considered to be the hardest problem for the development of new quantum technologies such as the Quantum Computer.

"After we have shaken the condensate with the pulse, it performs(exhibits) two different vibrational motions at the same time", says van Frank. "After a while, we shake the condensate a second time, recombining the two superimposed motions." Which of the two possible kinds of motion prevails in the end depends on the time delay between the two pulses and on the quantum phase of the superposition. Such a sequence of pulses is known as "Ramsey sequence" and is used for high-precision measurements in many areas. Now this technique was successfully transferred to the many-particle states of a Bose-Einstein condensate.

Just the Right Kick

In order to control the system, it was crucial to find exactly the right kind of pulse with which the condensate has to be shaken. It is supposed to enable a transition between the two vibration states that should be superimposed, but it should not be able to create any other possible states. Excluding all the other states turned out to be crucial for suppressing the unwanted decoherence effect.

"Our result proves that vibrational states of hundreds of atoms can be used for quantum experiments", says Schmiedmayer. These states can be used to store information, and one day maybe even to do calculations. The remarkable stability of these states also gives insight into decoherence phenomena of large systems, consisting of many particles – an extremely fruitful field of research. In a next step, not only vibrations but also rotation states of the Bose-Einstein condensate will be studied. In the quantum world, both are possible at the same time: shaken AND stirred.

INFORMATION: The work has now been published in the journal "Nature Communications". The team at the Vienna University of Technology was supported by researchers from Hamburg University and Ulm University. Nature Communications 5, 4009
doi:10.1038/ncomms5009

Picture Download: http://www.tuwien.ac.at/dle/pr/aktuelles/downloads/2014/shaken/

Additional Information:

Prof. Jörg Schmiedmayer
Institute of Atomic and Subatomic Phyisics,
Vienna Center for Quantum Science and Technology (VCQ)
Vienna University of Technology
Stadionallee 2, 1020 Wien
+43 (1) 58801 141888
schmiedmayer@AtomChip.org

Prof. Thorsten Schumm
Institute of Atomic and Subatomic Phyisics,
Vienna Center for Quantum Science and Technology (VCQ)
Vienna University of Technology
Stadionallee 2, 1020 Wien
T: +43-1-58801-141896
thorsten.schumm@tuwien.ac.at

Sandrine van Frank, MSc
Institute of Atomic and Subatomic Phyisics,
Vienna Center for Quantum Science and Technology (VCQ)
Vienna University of Technology
Stadionallee 2, 1020 Wien
T: +43-1-58801-141889
sandrine.frank@tuwien.ac.at

[Attachments] See images for this press release:
Shaken, not stirred: Control over complex systems consisting of many quantum particles

ELSE PRESS RELEASES FROM THIS DATE:

Five-question clinical tool the first to help screen risk of violence in military veterans

Five-question clinical tool the first to help screen risk of violence in military veterans
2014-06-04
CHAPEL HILL, N.C. -- A new brief, 5-question screening tool can help clinicians identify which veterans may be at greater risk of violence, according to a new study led by a UNC researcher. The study, published online by the American Journal of Psychiatry, is based on a national survey sample of veterans combined with a smaller, in-depth assessment sample. The screening tool, called the Violence Screening and Assessment of Needs (VIO-SCAN), asked veterans about financial stability, combat experience, alcohol misuse, history of violence or arrests, and probable posttraumatic ...

Mayo Clinic moves small-molecule drugs through blood-brain barrier

2014-06-04
ROCHESTER, Minn. — Researchers at Mayo Clinic have demonstrated in a mouse model that their recently developed synthetic peptide carrier is a potential delivery vehicle for brain cancer chemotherapy drugs and other neurological medications. The findings appear in PLOS ONE. "Not only have we shown that we can transport eight different molecules, we think this method will be less disruptive or invasive because it mimics a normal physiological process," says Mayo Clinic neuroscientist Gobinda Sarkar, Ph.D., the corresponding author of the study. The researchers are able ...

Finding the lost art of Angkor Wat

Finding the lost art of Angkor Wat
2014-06-04
Long-lost paintings have been discovered on the walls of Cambodia's ancient Angkor Wat temple, thanks to the keen observations of an Australian National University (ANU) researcher. The ancient paintings date back almost 500 years and depict deities, animals, boats and the temple itself, giving historians a new understanding of life in a relatively unknown period of Cambodia's history. Rock art researcher Noel Hidalgo Tan discovered the hidden images while working as a volunteer at an archaeological excavation in Angkor Wat during a university break in 2010. "I was ...

Four new genes confirmed to increase familial breast cancer risk

2014-06-04
SALT LAKE CITY— Four new genes have been added to the growing list of those known to cause increased breast cancer risk when mutated through the efforts of researchers at Huntsman Cancer Institute (HCI) at the University of Utah, who lead an international consortium working to find more gene mutations that cause inherited breast cancer susceptibilities. "BRCA1 and BRCA2 aren't the whole story when it comes to inherited breast cancer risk. We've known for a long time that more genes had to be responsible and several have since been discovered, by us and by others," according ...

Preserving bread longer: A new edible film made with essential oils

2014-06-04
Essential oils have boomed in popularity as more people seek out alternatives to replace their synthetic cleaning products, anti-mosquito sprays and medicines. Now scientists are tapping them as candidates to preserve food in a more consumer-friendly way. A study from ACS' Journal of Agricultural and Food Chemistry reports the development of new edible films containing oils from clove and oregano that preserve bread longer than commercial additives. Nilda de F. F. Soares and colleagues note that the search for new ways to keep packaged food from spoiling has led some ...

Quantum criticality observed in new class of materials

2014-06-04
Quantum criticality, the strange electronic state that may be intimately related to high-temperature superconductivity, is notoriously difficult to study. But a new discovery of "quantum critical points" could allow physicists to develop a classification scheme for quantum criticality -- the first step toward a broader explanation. Quantum criticality occurs in only a few composite crystalline materials and happens at absolute zero -- the lowest possible temperature in the universe. The paucity of experimental observations of quantum criticality has left theorists wanting ...

Understanding mussels' stickiness could lead to better surgical and underwater glues

2014-06-04
Mussels might be a welcome addition to a hearty seafood stew, but their notorious ability to attach themselves to ships' hulls, as well as to piers and moorings, makes them an unwelcome sight and smell for boaters and swimmers. Now, researchers report in ACS' journal Langmuir a clearer understanding of how mussels stick to surfaces, which could lead to new classes of adhesives that will work underwater and even inside the body. Shabeer Ahmad Mian and colleagues note that mussels have a remarkable knack for clinging onto solid surfaces underwater. That can make them a ...

E-cigarettes: More than just hot air

2014-06-04
E-cigarettes are a potential smoking cessation aid and they may also be able to lower the risk of nicotine dependency in high-risk groups. The available scientific evidence, however, remains insufficient. This is the conclusion reached by Dennis Nowak et al. from Munich in this issue of Deutsches Ärzteblatt International (Dtsch Arztebl Int 2014; 111: 349–55). The authors performed a systematic literature search for data on e-cigarettes' mechanism of action, their emissions, how they are seen by groups of potential users, their efficacy in smoking cessation, and their addiction ...

BMJ urged to widen its approach to transparency

2014-06-04
A group of New Zealand health policy researchers from the University of Otago's Dunedin and Christchurch campuses has called on the leading medical journal BMJ to be much more even handed in scrutinizing the transparency of what it publishes. Professor Robin Gauld, the Director of the Centre for Health Systems, has co-written a letter that has appeared in the BMJ on 31 May, expressing concern about a journal editorial reviewing a report into the performance of the Canterbury District Health Board (CDHB) prepared by the King's Fund in England. The report, released in ...

First demonstration in human cells of chromosomal translocations that cause certain cancer

2014-06-04
Scientists at the Centro Nacional de Investigaciones Cardiovasculares (CNIC) and the Centro Nacional de Investigaciones Oncológicas (CNIO) have succeeded in reproducing, in human cells, the chromosomal translocations that cause two types of cancer: acute myeloid leukemia and Ewing's sarcoma. The findings, published today in Nature Communications, open the way to the development of new therapeutic targets for the treatment of these cancers. The study was led by Juan Carlos Ramírez and Raúl Torres, of the CNIC Viral Vectors Unit, and Sandra Rodríguez-Perales, of the Molecular ...

LAST 30 PRESS RELEASES:

KAIST Develops Retinal Therapy to Restore Lost Vision​

Adipocyte-hepatocyte signaling mechanism uncovered in endoplasmic reticulum stress response

Mammals were adapting from life in the trees to living on the ground before dinosaur-killing asteroid

Low LDL cholesterol levels linked to reduced risk of dementia

Thickening of the eye’s retina associated with greater risk and severity of postoperative delirium in older patients

Almost one in ten people surveyed report having been harmed by the NHS in the last three years

Enhancing light control with complex frequency excitations

New research finds novel drug target for acute myeloid leukemia, bringing hope for cancer patients

New insight into factors associated with a common disease among dogs and humans

Illuminating single atoms for sustainable propylene production

New study finds Rocky Mountain snow contamination

Study examines lactation in critically ill patients

UVA Engineering Dean Jennifer West earns AIMBE’s 2025 Pierre Galletti Award

Doubling down on metasurfaces

New Cedars-Sinai study shows how specialized diet can improve gut disorders

Making moves and hitting the breaks: Owl journeys surprise researchers in western Montana

PKU Scientists simulate the origin and evolution of the North Atlantic Oscillation

ICRAFT breakthrough: Unlocking A20’s dual role in cancer immunotherapy

How VR technology is changing the game for Alzheimer’s disease

A borrowed bacterial gene allowed some marine diatoms to live on a seaweed diet

Balance between two competing nerve proteins deters symptoms of autism in mice

Use of antifungals in agriculture may increase resistance in an infectious yeast

Awareness grows of cancer risk from alcohol consumption, survey finds

The experts that can outsmart optical illusions

Pregnancy may reduce long COVID risk

Scientists uncover novel immune mechanism in wheat tandem kinase

Three University of Virginia Engineering faculty elected as AAAS Fellows

Unintentional drug overdoses take a toll across the U.S. unequally, study finds

A step toward plant-based gelatin

ECMWF unveils groundbreaking ML tool for enhanced fire prediction

[Press-News.org] Shaken, not stirred: Control over complex systems consisting of many quantum particles
At TU Vienna, a new method was developed to utilize quantum mechanical vibrations for high precision measurements; The well-known concept of the Ramsey interferometer is applied to a complex multi particle system consisting of hundreds of atoms