Atomic Force Microscope Manipulate Atoms to Form Smallest Swiss Cross

Researchers from Finland and Japan have formed the smallest Swiss cross using bromide atoms on a sodium chloride surface. The academic journal Nature Communications has published the team's results.

The team used bromine atoms, 20 of them, and positioned these on a sodium chloride surface to form the cross. Using an atomic force microscope, the structure was found to be stable at room temperature. The bromine atoms were exchanged with the chlorine atoms to make the structure; by moving and positioning the single atoms.

It is the first time that systematic atomic manipulation on an insulating surface have been achieved at room temperature. The resulting Swiss cross measures 5.6 nanometers square.

This discovery can lead to the development of next generation electromechanical systems, advanced atomic-scale data storage devices and logic circuits.

Atomic Movement Recorded In Real Time Through Femtosecond Electron Diffraction

Scientists at the University of Toronto were able to observe and record motions of atoms in real time. This is a huge development on the understanding chemistry and biology at the atomic level.

For the first time atomic movement as they undergo chemical transformation has been directly recorded through a process called electron diffraction. As the atoms convert into new structures and adopt new properties, scientists observed and recorded this transitional state as it happens.

For the process to work, an ultrabright femtosecond electron source is used to light up the molecular motions in the organic crystal during its transition phase. Using three key reaction coordinates within the crystal, scientists were able to reconstruct the structural evolution of its molecular system.

Combining the coordinates to make a 3D model and using Femtosecond Electron Diffraction, the duration of the transition and position of the moluecules as well as its reaction trajectory is obtained. (See video)

Linac Coherent Light Source Experiments On Chemical Reactions Lead To Clean Energy Development

New experiments at the Linac Coherent Light Source, an X-ray free-electron laser, took an unprecedented look at the way carbon monoxide molecules react with the surface of a catalyst in real time.
Credit: Greg Stewart / SLAC National Accelerator Laboratory

Ongoing experiments at the Linac Coherent Light Source Facility aimed at observing chemical reactions within catalysts may lead into better and more efficient clean energy technologies.

The Linac Coherent Light Source (LCLS) is a free electron laser facility located at the Stanford Linear Accelerator Center (SLAC). A free electron laser (FEL) is a laser that has the same optical properties of a conventional laser but uses a different principle in forming the laser beam. Free electron lasers use an electron beam which moves freely through a magnetic structure. Conventional lasers use electrons in an excited bound atomic or molecular state.

The LCLS uses ultra-fast x-ray pulses 10⁹ times brighter than traditional synchotron (a type of particle accelerator) x-rays. The x-rays are used to image objects at an atomic level. The wavelength generated by the LCLS is close to the width of an atom which allows a very detailed image at a level thought to be impossible.

The X-ray pulses are used much like flashes from a high-speed strobe light, enabling scientists to take stop-motion pictures of atoms and molecules in motion, shedding light on the fundamental processes of chemistry, technology, and life itself.

Physicists Cool OH Molecules To Near Absolute Zero Through Evaporative Cooling

Researchers have created a process that can cool molecules to near absolute zero temperatures through evaporative cooling. Previous processes were then limited to ultra-cooling atoms.

Ultra cold atom physics deals with atoms that are at a temperature close to absolute 0 or 0 K (kelvins). In this field of science, temperature is measured at the nanoscale or at nano-kelvins (nK).

JILA researchers developed a new magnetic trap and a new technique to achieve "evaporative cooling" of hydroxyl molecules (one hydrogen atom bonded to one oxygen atom). A microwave pulse at a specific frequency converts hot molecules inside the trap to a slightly different energy state. A small electric field is pulsed on briefly to destabilize and eject these converted molecules from the trap. As the microwave frequency is slowly altered, molecules distributed inside the trap (which has a varied magnetic field strength) are progressively converted and removed from the top of the trap, where molecules are hotter, to the bottom, where molecules are cooler.
Credit: Baxley and Ye Group/JILA

Since it is impossible to bring an object to absolute zero (as stated in the Third Law of Thermodynamics), ultracold atom physics study objects that are close to absolute zero. The coldest an atom has been brought down to is 0.45 nK (nano kelvin) or 4.5 x 10^-10 K or 0.00000000045 K.

At these levels, atoms start to behave differently and their properties start to move from classical physics to quantum mechanics.

A property that scientists are interested in is the transformation of atoms into a new form of matter called the Bose-Einstein Condensate (BEC). The Bose-Einstein condensate happens when atoms that are brought down to near absolute zero start to behave like waves rather than particles.

As the temperature goes down, these atoms start to vibrate in the same wavelength. Because of this, they start to behave like a single mass object, the Bose-Einstein condensate.

Laser cooling and evaporative cooling are the two ways that scientists use to lower the temperature of atoms. Laser cooling in simple terms uses laser light on atoms to manipulate photons to lowers the energy level of the atom

With evaporative cooling, atoms with higher energy levels (temperature) are ejected out of an optical or magnetic trap until only atoms with the lowest energy levels are left. BECs and ultracold atoms are at very low temperatures are highly sensitive to heat (2nd Law of Thermodynamics).

Practical applications of ultracold atom physics range from super sensitive sensors to atom chips used in diodes and semiconductors. Current technologies used by magnetic levitation (mag-lev) trains, quantum computers and MRI devices utilize principles behind ultracold atom physics.

Light Pulses From Quark Gluon Plasma To Accurately Measure Time in Septillionths of a Second

Scientists have proposed using the light pulse emitted by a quark gluon plasma, a newly discovered state of matter, as a way of measuring time at precise levels of yoctoseconds which is a septillionth of a second (1x10^-24).

A quark gluon plasma (QGP) is a new state of matter that results from the collision of two nuclei. It is made up of two of matters building blocks, the quark and the gluon.

The image illustrates two lead atoms colliding to form a quark gluon plasma which in turn emits a short light pulse.

Quarks and Gluons

Quarks are one of the tiniest building blocks of matter. The proton and neutron inside an atom are made up of these quarks. A particle made up of quarks is called a hadron. Particles made up of quarks are called hadrons.

Japan's Riken Edges Closer To Naming Atomic Element 113

Elements are identified by their atomic numbers. The atomic number corresponds to the number of protons found in the element's nucleus.

Elements found in the atomic table greater than atomic number 92 are called heavy elements. Those that are past atomic number 112 are called superheavy elements. Although each element has a fixed number of protons, it can vary in the number of neutrons present. These variations of the same element are called isotopes.

Superheavy elements are unstable and radioactive. The half-life of these elements are very short, lasting mere microseconds and for some, even in nanoseconds. The half-life is the time in which half the atoms of an isotope starts to decay and break down. Scientists predict that elements within a region of atomic number 114 and up will have a more longer and stable half-life. These predicted elements are what they call the "island of stability".

One superheavy atom that has been involved in a race to its definite discovery is element 113. Temporarily named Ununtrium (un-un-tri-um: 113), the element is being claimed by two groups. A team of Russian scientists at Dubna (Joint Institute for Nuclear Research) and American scientists at the Lawrence Livermore National Laboratory reported their experimental report pertaining to this element in August 2003.

On July 23, 2004, a team of Japanese scientists at RIKEN, Japan's premier science research institute, reported their detection of ununtrium in their experiments. They again produced another ununtrium atom in April 2005.

In 2011, the International Union of Pure and Applied Chemistry (IUPAC) evaluated the 2004 RIKEN experiments and 2004 and 2007 Dubna experiments. The scientific body concluded that both groups did not meet the criteria for the discovery of the element.

Search for element 113 concluded at last

The most unambiguous data to date on the elusive 113th atomic element has been obtained by researchers at the RIKEN Nishina Center for Accelerator-based Science (RNC). A chain of six consecutive alpha decays, produced in experiments at the RIKEN Radioisotope Beam Factory (RIBF), conclusively identifies the element through connections to well-known daughter nuclides. The groundbreaking result, reported in the Journal of Physical Society of Japan, sets the stage for Japan to claim naming rights for the element.

The search for superheavy elements is a difficult and painstaking process. Such elements do not occur in nature and must be produced through experiments involving nuclear reactors or particle accelerators, via processes of nuclear fusion or neutron absorption. Since the first such element was discovered in 1940, the United States, Russia and Germany have competed to synthesize more of them. Elements 93 to 103 were discovered by the Americans, elements 104 to 106 by the Russians and the Americans, elements 107 to 112 by the Germans, and the two most recently named elements, 114 and 116, by cooperative work of the Russians and Americans.

Quantum Effects in Cold Atom Physics Through Pre-Thermalization Are More Than Expected

On an atom chip (top), clouds of ultracold atoms (red) are created. They are allowed to interfere, creating an ordered matter-wave interference pattern (bottom).
Credit: Vienna University of Technology

Absolute zero is measured at 0 kelvins. The 3rd law of thermodynamics dictate that it is impossible to cool down an object to exactly 0 kelvins. Since cold is the absence of heat, absolute zero would mean that there is no heat left in the object or system. In 2003, MIT Researchers achieved the lowest temperature which is .45 nK (nano kelvin) or 4.5 x 10-10 K or 0.00000000045 K.

Ultracold atoms are atoms that are maintained at temperatures close to absolute zero. The study that uses ultracold atoms in relation to fundamental quantum phenomena is called Cold Atom Physics. Applications for this technology range from quantum computers, and quantum simulators to ultra-high-precision atomic clocks and quantum metrology.

One of the basic underlying phenomenon of cold atom physics is the Boss-Einstein Condensate (BEC). This is a new state of mater that forms in very low temperatures. When atoms are cooled down to very low temperatures, they start to behave in wave like properties, as the temperature keeps going down, they start to merge and behave like one singular wave like particle. This was predicted by Satyendra Nath Bose and Albert Einstein in 1924–25 and was successfully produced and observed in 1995.

Ultracold atoms reveal surprising new quantum effects

Every day we observe systems thermalizing: Ice cubes in a pot of hot water will melt and will never remain stable. The molecules of the ice and the molecules of the water will reach thermal equilibrium, ending up at the same temperature. Well-ordered ice crystals turn into a disordered liquid.

Experiments at the Vienna Center for Quantum Science and Technology (VCQ) at the Vienna University of Technology have shown that in the quantum world the transition to thermal equilibrium is more interesting and more complicated than assumed so far.

New Process In Isolating Graphene Leads To Next Generation Devices

Graphene is a material derived from graphite. It is two dimensional and consists of a single layer of carbon atoms arranged in a honeycomb structure. This structure resembles chicken wire.

Graphene is the thinnest known material and is also the strongest. It conducts electricity as efficiently as copper and outperforms all other materials as a conductor of heat. Graphene is almost completely transparent, yet so dense that even the smallest atom helium cannot pass through it.

Andre Geim and Konstantin Novoselov (the two scientists who successfully isolated the material and won the 2010 Nobel Prize for it) defined graphene as "a flat monolayer of carbon atoms tightly packed into a two-dimensional (2D) honeycomb lattice, and is a basic building block for graphitic materials of all other dimensionalities. It can be wrapped up into 0D fullerenes, rolled into 1D nanotubes or stacked into 3D graphite."

Graphene is a material that has the potential to create foldaway mobile phones, wallpaper-thin lighting panels and the next generation of aircraft.

A graphene circuit can operate at high frequencies of up to 10GHz (10 billion cycles per second), and at temperatures of up to 127°C. It is the most transparent, strongest and most conductive material on Earth.

Cutting the graphene cake

Sandwiching individual graphene sheets between insulating layers in order to produce electrical devices with unique new properties, the method could open up a new dimension of physics research.

Writing in Nature Materials, the scientists show that a new side-view imaging technique can be used to visualize the individual atomic layers of graphene within the devices they have built. They found that the structures were almost perfect even when more than 10 different layers were used to build the stack.

This surprising result indicates that the latest techniques of isolating graphene could be a huge leap forward for engineering at the atomic level.

This development gives more weight to graphene's suitability as a major component in the next generation of computer chips.

The researchers' side-view imaging approach works by first extracting a thin slice from the centre of the device. This is similar to cutting through a rock to reveal the geological layers or slicing into a chocolate gateaux to reveal the individual layers of icing.

Cheaper, Stable and More Accurate Magnetic Field Sensor Using Organic Spintronics Developed

What is Spintronics?

Spintronics is a new field of science technology which deals in the physics of the spin of an electron and its relation to the generated electronic charge. It is also known as spin electronics and magnetoelectronics.

Most current electronic devices use silicon to rely on the transport of electrical charge of electrons. Physicists are now trying to utilize the intrisinc spin of an electron as well as the charge it generates (or just only the spin) for operating a device; a spintronic device. It is said that spintronics based devices are smaller, cheaper, stable and more accurate than existing conventional devices.

Spin makes a particle behave like a tiny bar magnet that is pointed up or down within an electron or a nucleus. Down can represent 0 and up and represent 1, similar to how in electronics no charge represents 0 and a charge represents 1. Spintronics allows more information, the 0 or 1 charge and the 0 or 1 spin, to be used than electronics which just uses the 0 or 1 charge.

Spintronic devices act according to the following scheme:

1. Information is stored (written) into spins as a particular spin orientation (up or down)
2. The spins, being attached to mobile electrons, carry the information along a wire
3. The information is read at a terminal.

The spin orientation lasts longer than electron momentum (nanoseconds compared to femtoseconds). This makes it optimal for applications such as memory storage and magnetic sensors applications. It has more promising use in quantum computing where electron spin would represent a bit (called qubit) of information

Currently, the read heads of modern computer hard drives utilize spintronics through GMR or Giant Magnetoresistance. Depending on the alignment of the spin in relation to two layers of ferromagnetic materials, the device can detect the resistance generated. This change in resistance (also called magnetoresistance) is used to sense changes in magnetic fields. This is ultimately converted into data the computer can understand.

Spintronic device uses thin-film organic semiconductor

University of Utah physicists developed an inexpensive, highly accurate magnetic field sensor for scientific and possibly consumer uses based on a "spintronic" organic thin-film semiconductor that basically is "plastic paint."

The new kind of magnetic-resonance magnetometer also resists heat and degradation, works at room temperature and never needs to be calibrated, physicists Christoph Boehme, Will Baker and colleagues report online in the Tuesday, June 12 edition of the journal Nature Communications.

The magnetic-sensing thin film is an organic semiconductor polymer named MEH-PPV. Boehme says it really is nothing more than an orange-colored "electrically conducting, magnetic field-sensing plastic paint that is dirt cheap. We measure magnetic fields highly accurately with a drop of plastic paint, which costs just as little as drop of regular paint."

To Commemorate 2012 London Olympics, Smallest Five Ringed Structure Olympicene Produced and Imaged

Olympicene
Credit: IBM Research - Zurich, University of Warwick, Royal Society of Chemistry

Olympicene is a five ringed molecule that was synthesized to resemble the five olympic rings and commemorate the 2012 London Olympics.

Although Olympiadane was already named for resembling the five interlocking Olympic rings, the creators of Olympicene synthesized the molecule from Benzo[CD]pyrene which already looks like the Olympic rings. They find Benzo[CD]pyrene looking more like the rings and that Olympiadane is more complex to synthesize.

Olympicene has the chemical formula C19H12 and has an average mass of 240.298599 Daltons (1 Da= 1g/mol). It's monoisotopic mass is 240.093903 Da.

Stunning image of smallest possible 5 rings

Scientists have created and imaged the smallest possible five-ringed structure – about 100,000 times thinner than a human hair – and you'll probably recognise its shape.

A collaboration between the Royal Society of Chemistry (RSC), the University of Warwick and IBM Research – Zurich has allowed the scientists to bring a single molecule to life in a picture, using a combination of clever synthetic chemistry and state-of-the-art imaging techniques.

The scientists decided to make and visualise olympicene whose five-ringed structure was entered on ChemSpider, the RSC's free online chemical database of over 26 million records two years ago.

Europe's First Neutron Source, European Spallation Source (ESS), To Be Operational By 2019

A device that emits neutrons is called a Neutron Source. There are different kinds of neutron sources from a small hand held radioactive source to large neutron research facilities operating research reactors and spallation sources.

The large facility neutron source such as the ones found in Oxfordshire, utilizes a low energy reaction coupled with a high-current, variable-pulse-width proton accelerator to produce either short or long neutron pulses.

Sweden to host a new neutron source

By 2019, Europe will have its first operational Neutron Source. Currently under development, its aim is to produce beams of neutrons that can penetrate into the heart of matter without damaging it and reveal its secrets.

The European Spallation Source (ESS) will be constructed starting next year, at the southern end of Sweden, in a town called Lund.

“The ESS is the result of an idea that began 20 years ago!” underlines Mats Lindroos, in charge of the ESS Accelerator Division. “Today, 17 European countries support the project, including Sweden, Denmark and Norway, who together account for 50% of the construction funding.”

The design of the neutron source is a collaboration of different nations that participated in the project. The facility also boasts of staff, technology, expertise, and skill from European research centres such as CERN. “CERN is participating in the development of the entire accelerator part,” explains Christine Darve, the engineer responsible for the cryomodule portion. “For the ESS target, which will be made of tungsten, we are cooperating above all with nuclear physics experts.”