Phase change materials that change their optical properties depending on the arrangement of the atoms allow for the storage of several bits in a single cell.
novel materials that change their optical properties depending on the arrangement of the atoms: Within shortest periods of time, they can change between crystalline (regular) and amorphous (irregular) states.
including one at NIST using atoms in 2004. Arraythe lead author, Hiroki Takesue, was a NIST guest researcher from NTT Corp. in Japan.
"Previously, researchers thought quantum repeaters might need to rely on atoms or other matter, instead of light,
A sheet of graphene is an ultrathin lattice of carbon atoms that is one atom thick, so pores in graphene are defined at the atomic scale.
which--given the single-atom thickness of graphene--makes them among the smallest pores through
it is due to the canting between the atomic magnets from one atom to the next. The larger the angle between the adjacent atomic magnets, the stronger is the change in electrical resistance.'
a process of aligning atoms inside a diamond so they create a signal detectable by an MRI SCANNER."
Graphene is a two-dimensional sheet of carbon atoms, just one atom thick. Its flexibility, optical transparency and electrical conductivity make it suitable for a wide range of applications,
which carries a supply of iron atoms that every cell needs as components of metabolic enzymes.
The scientists coat gold nanoparticles of a few thousand atoms each with an oil-like organic molecule that holds the gold particles together.
or about six atoms thick, is so tiny it would not normally be measurable. Subramanian Sankaranarayanan and Sanket Deshmukh at CNM used the high-performance computing resources at DOE National Energy Research Scientific Computing Center and the Argonne Leadership Computing Facility (ALCF
At temperatures approaching absolute zero, atoms cease their individual, energetic trajectories, and start to move collectively as one wave.
if atoms cannot be kept cold or confined. The MIT team combined several techniques in generating ultracold temperatures,
the John D. Macarthur Professor of Physics at MIT. e use ultracold atoms to map out
originally co-developed by Ketterle, to cool atoms of rubidium to nanokelvin temperatures. Atoms of rubidium are known as bosons,
for their even number of nucleons and electrons. When cooled to near absolute zero bosons form what called a Bose-Einstein condensate a superfluid state that was discovered first co by Ketterle,
After cooling the atoms, the researchers used a set of lasers to create a crystalline array of atoms,
or optical lattice. The electric field of the laser beams creates what known as a periodic potential landscape, similar to an egg carton,
whether this could be done with ultracold atoms in an optical lattice. Since the ultracold atoms are charged not,
as electrons are, but are instead neutral particles, their trajectories are unaffected normally by magnetic fields. Instead, the MIT group came up with a technique to generate a synthetic
ultrahigh magnetic field, using laser beams to push atoms around in tiny orbits, similar to the orbits of electrons under a real magnetic field.
and two additional laser beams to control the motion of the atoms. On a flat lattice, atoms can easily move around from site to site.
However, in a tilted lattice, the atoms would have to work against gravity. In this scenario, atoms could only move with the help of laser beams. ow the laser beams could be used to make neutral atoms move around like electrons in a strong magnetic field
added Kennedy. Using laser beams, the group could make the atoms orbit, or loop around, in a radius as small as two lattice squares, similar to how particles would move in an extremely high magnetic field. nce we had the idea,
we were excited really about it, because of its simplicity. All we had to do was take two suitable laser beams
and carefully align them at specific angles, and then the atoms drastically change their behavior,
Kennedy says. ew perspectives to known physics After developing the tilting technique to simulate a high magnetic field,
and electronic controls to avoid any extraneous pushing of the atoms, which could make them lose their superfluid properties. t a complicated experiment, with a lot of laser beams, electronics,
During that time, the team took time-of-flight pictures of the distribution of atoms to capture the topology
but to add strong interactions between ultracold atoms, or to incorporate different quantum states, or spins.
Graphene is only one atom thick material, which conducts electricity and heat with such efficiency that it is likely to revolutionize electronics.
This involves exciting a single atom with just a tiny amount of light. The theory states that the light scattered by this atom should,
similarly, be squeezed. Unfortunately, although the mathematical basis for this method known as squeezing of resonance fluorescence was drawn up in 1981,
or photons, using an artificially constructed atom, known as a semiconductor quantum dot. Thanks to the enhanced optical properties of this system and the technique used to make the measurements,
because we now have artificial atoms with optical properties that are superior to natural atoms.
In the Cambridge experiment, the researchers achieved this by shining a faint laser beam on to their artificial atom, the quantum dot.
and Stanford university shows how individual atoms move in trillionths of a second to form wrinkles on a three-atom-thick material.
The electrons of the probe pulse scatter off the monolayer atoms (blue and yellow spheres)
which uses energetic electrons to take snapshots of atoms and molecules on timescales as fast as 100 quadrillionths of a second. his is published the first scientific result with our new instrument,
This animation explains how researchers use high-energy electrons at SLAC to study faster-than-ever motions of atoms and molecules relevant to important materials properties and chemical processes.
Until now, researchers only had limited a view of the underlying mechanisms. he functionality of 2-D materials critically depends on how their atoms move,
to take snapshots of a three-atom-thick layer of a promising material as it wrinkles in response to a laser pulse.
scatter off the sample atoms and produce a signal on a detector that scientists use to determine where atoms are located in the monolayer.
This technique is called ultrafast electron diffraction. Illustrations (each showing a top and two side views) of a single layer of molybdenum disulfide (atoms shown as spheres.
Top left: In a hypothetical world without motions, the dealmonolayer would be flat. Top right:
when atoms are brought too close together to detect a wide array of protein markers that are linked to various diseases.
when atoms are brought too close together to detect a wide array of protein markers that are linked to various diseases.
a nanomaterial consisting of graphite that is extremely thin measuring the thickness of a single atom.
Graphene is a two-dimensional sheet of carbon atoms, just one atom thick. Its flexibility, optical transparency and electrical conductivity make it suitable for a wide range of applications,
Unlike conventional drugs, where chemists exert exquisite control over the position of every atom, with proteins they mostly still need a living thing to do their manufacturing for them. hen you get to whole proteins,
Called sol-gel thin film, it is made up of a single layer of silicon atoms and a nanoscale self-assembled layer of octylphosphonic acid.
This material--just a single layer of atoms--could be made as a wearable device perhaps integrated into clothing to convert energy from your body movement to electricity
when the size of material shrinks to the scale of a single atom Hone adds.
because each nucleotide has a slightly different distribution of electrons the negatively charged parts of the atoms.
The researchers extensively used the Blue waters supercomputer at the National Center for Supercomputing Applications housed at the University of Illinois. They mapped each individual atom in the complex DNA molecule
and are composed of 10-20 atoms that are segregated to the surface. The unique environment around the Pd-islands give rise to special effects that all together turn the islands into highly efficient catalytic hot-spots for oxygen reduction.
This is the first time that anyone has imaged directly single dopant atoms moving around inside a material said Rohan Mishra of Vanderbilt University who is also a visiting scientist in ORNL's Materials science and Technology Division.
Semiconductors which form the basis of modern electronics are doped by adding a small number of impure atoms to tune their properties for specific applications.
The study of the dopant atoms and how they move or diffuse inside a host lattice is a fundamental issue in materials research.
Traditionally diffusion of atoms has been studied through indirect macroscopic methods or through theoretical calculations. Diffusion of single atoms has previously been observed directly only on the surface of materials.
The experiment also allowed the researchers to test a surprising prediction: Theory-based calculations for dopant motion in aluminum nitride predicted faster diffusion for cerium atoms than for manganese atoms.
This prediction is surprising as cerium atoms are larger than manganese atoms. It's completely counterintuitive that a bigger heavier atom would move faster than a smaller lighter atom said the Material Science and Technology Division's Andrew Lupini a coauthor of the paper.
In the study the researchers used a scanning transmission electron microscope to observe the diffusion processes of cerium and manganese dopant atoms.
The images they captured showed that the larger cerium atoms readily diffused through the material
while the smaller manganese atoms remained fixed in place. The team's work could be applied directly in basic material design
and technologies such as energy saving LED LIGHTS where dopants can affect color and atom movement can determine the failure modes.
Diffusion governs how dopants get inside a material and how they move said Lupini. Our study gives a strategy for choosing
which dopants will lead to a longer device lifetime. The study was funded by the DOE Office of Science the Australian Research Council Vanderbilt University and the Japan Society for the Promotion of Science Postdoctoral Fellowship for research abroad.
because the parallel alignment of adjacent electron spins in the iron atoms generates a strong internal magnetic field.
At somewhat lower temperatures the iron atoms in the (Life) OH layer become ferromagnetic but superconductivity persists nevertheless.
or two atoms thick--actually move at any given time. As these outer layers of atoms move across the surface and redeposit elsewhere they give the impression of much greater movement
--but inside each particle the atoms stay perfectly lined up like bricks in a wall.
The interior is crystalline so the only mobile atoms are the first one or two monolayers Li says.
Everywhere except the first two layers is crystalline. By contrast if the droplets were to melt to a liquid state the orderliness of the crystal structure would be eliminated entirely--like a wall tumbling into a heap of bricks.
In an LED atoms can be forced to emit roughly 10 million photons in the blink of an eye.
That gap turned out to be just 20 atoms wide. But that wasn't a problem for the researchers.
Electron microscopy experiments revealed the presence of tungsten dimers paired tungsten atoms arranged in chains responsible for the key distortion from the classic octahedral structure type.
#Discovery of new subatomic particle, type of meson, to transform understanding of fundamental force of nature The discovery of a new particle will transform our understanding of the fundamental force of nature that binds the nuclei of atoms researchers argue.
Led by scientists from the University of Warwick the discovery of the new particle will help provide greater understanding of the strong interaction the fundamental force of nature found within the protons of an atom's nucleus. Named Ds3*(2860) the particle
and also for holding electrons in orbit around an atom's nucleus. The strong interaction is the force that binds quarks the subatomic particles that form protons within atoms together.
These sparks knock atoms out of the material resulting in a plasma that emits multicolored light.
atom-thick strips of carbon created by splitting nanotubes, a process also invented by the Tour lab
the researchers are able to directly observe individual atoms at the interface of two surfaces
By changing the spacing of atoms on one surface, they observed a point at which friction disappears.
When atoms travel across such an electric field, they are drawn to places of minimum potential in this case, the troughs.
an ion crystal essentially, a grid of charged atoms in order to study friction effects, atom by atom.
or charge, neutral ytterbium atoms emerging from a small heated oven, and then cooled them down with more laser light to just above absolute zero.
The charged atoms can then be trapped using voltages applied to nearby metallic surfaces. Once positively charged, each atom repels each other via the so-called oulomb force.
The repulsion effectively keeps the atoms apart, so that they form a crystal or latticelike surface.
The team then used the same forces that are used to trap the atoms to push
and pull the ion crystal across the lattice, as well as to stretch and squeeze the ion crystal,
much like an accordion, altering the spacing between its atoms. An earthquake and a caterpillarin general, the researchers found that
when atoms in the ion crystal were spaced regularly, at intervals that matched the spacing of the optical lattice, the two surfaces experienced maximum friction,
when atoms are spaced so that each occupies a trough in the optical lattice, when the ion crystal as a whole is dragged across the optical lattice,
the atoms first tend to stick in the lattice troughs, bound there by their preference for the lower electric potential,
as well as by the Coulomb forces that keep the atoms apart. If enough force is applied, the ion crystal suddenly slips,
as the atoms collectively jump to the next trough. t like an earthquake, Vuletic says. here force building up,
and squeeze the ion crystal to manipulate the arrangement of atoms, and discovered that if the atom spacing is mismatched from that of the optical lattice,
friction between the two surfaces vanishes. In this case the crystal tends not to stick then suddenly slip,
For instance, in arrangements where some atoms are in troughs while others are at peaks, and still others are somewhere in between,
one atom may slide down a peak a bit, releasing a bit of stress, and making it easier for a second atom to climb out of a trough
which in turn pulls a third atom along, and so on. hat we can do is adjust at will the distance between the atoms to either be matched to the optical lattice for maximum friction,
or mismatched for no friction, Vuletic says. Gangloff adds that the group technique may be useful
not only for realizing nanomachines, but also for controlling proteins, molecules, and other biological components. n the biological domain, there are various molecules
and atoms in contact with one another, sliding along like biomolecular motors, as a result of friction or lack of friction, Gangloff says. o this intuition for how to arrange atoms so as to minimize
or maximize friction could be applied. obias Schaetz, a professor of physics at the University of Freiburg in Germany, sees the results as a lear breakthroughin gaining insight into therwise inaccessible fundamental physics.
uning friction atom-by-atom in an ion-crystal simulator, Science 5 june 2015: Vol. 348 no. 6239 pp. 1115-1118;
and that as soon as a part of our bodies is made of titanium atoms or something it s less human that you can't embed humanity into synthetics.
and some differ by just an atom or two so they're hard to tell apart.
#Scientists use graphene to create the world's smallest light bulb Scientists have created the world's smallest light bulb from a one atom-thick layer of graphene,
is composed of layers of carbon laid down in a lattice structure just one atom thick.
Scientists have created the world's smallest light bulb from a one atom-thick layer of graphene
is composed of layers of carbon laid down in a lattice structure just one atom thick.
graphene is a 2d material that consists of a hexagonal sheet only a single atom thick.
#Researchers Create Unexpected Shapes of Mesoscale Atoms In the prestigious physics journal"Physical Review Letters"a team of researchers from the Institute of Physical chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw,
As a result, the number of different structures of mesoscale atoms it was possible to obtain was limited very."
The existence of the second parameter significantly enhances the ability to form new mesoscale atoms.
Depending on the configuration--the number of droplets within the drop and the ratio between the volumes of all the droplets--a unique structure of a mesoscale atom formed.
The researchers could observe a number of distinct geometries of the atoms. A real surprise was that they could also observe structures containing all core droplets arranged in a row
The mesoscale atoms of droplets within drops obtained by the team from IPC PAS had just sub-millimeter dimensions,
"The controlled production of mesoscale atoms from droplets is of particular importance for materials science. This is because materials come into being in a manner somewhat similar to structures made of building blocks:
they are made up'of many smaller'bricks'--tightly packed clusters of particles or atoms. A promising area of use seems to be the transport of drugs to specific areas of the body.
Each drop in the mesoscale atom could contain various therapeutic substances which would be released under different conditions.
These arrays of nanoparticles with predictable geometric configurations are somewhat analogous to molecules made of atoms.
While atoms form molecules based on the nature of their chemical bonds, there has been no easy way to impose such a specific spatial binding scheme on nanoparticles.
"This framework also contains organic molecules and functional atoms, such as nitrogen, which allow us to tune the electronic properties of the carbon."
They directly examined separate atoms at the interface of two surfaces and altered their arrangement by tuning the quantity of friction between the surfaces.
The atoms are attracted to areas with minimum potential (trough area) when they pass such an electric field.
The ion crystal is charged a atomic grid created by Vuletic to analyze the effects of friction, atom by atom.
or charge neutral ytterbium atoms rising from a tiny heated oven. The atoms were cooled then down with more laser light to a temperature immediately above absolute zero.
Using voltages applied to metallic surfaces in very close proximity, it is possible to trap charged atoms.
When positively charged the atoms begin to repel each other due to the Coulomb force. The repulsion successfully maintains the atoms at a distance from each other,
such that they form lattice-or crystal-like surfaces. The MIT physicists applied the same forces used for trapping the atoms to pull
and push the ion crystal over the lattice, and to squeeze and stretch the ion crystal, in a motion similar to an accordion,
to modify the atomic spacing. They observed that the two surfaces underwent maximum friction, similar to two complementary Lego bricks,
when atoms in the ion crystal were spaced normally at intervals equaling the optical lattice spacing.
when the atomic spacing is such that each atom occupies a trough in the optical lattice,
initially the atoms tend to adhere to the troughs of the lattice. This occurs due to their tendency to be attracted to a lower electric potential,
and because of the Coulomb forces that cause the atoms to repel. However, when a certain level of force is used, the ion crystal abruptly slips,
as the atoms jointly move to the next trough. t like an earthquake, Vuletic says. here force building up,
and squeezing the ion crystal in order to influence the arrangement of atoms. They found that if the atom spacing did not match that of the optical lattice,
friction between the two surfaces disappeared. In this situation, the crystal is inclined not to stick, and abruptly slips,
For example, in arrangements wherein certain atoms are in troughs, certain stoms in peaks, and other atoms in between troughs and peaks,
when the ion crystal is transferred across the optical lattice, one atom may move down a peak providing a little stress for another atom to move up a trough,
which may help pull another atom and so on. hat we can do is adjust at will the distance between the atoms to either be matched to the optical lattice for maximum friction,
or mismatched for no friction, Vuletic says. Gangloff adds that the team method can be used in other areas such as for controlling proteins, molecules,
and atoms in contact with one another, sliding along like biomolecular motors, as a result of friction or lack of friction, Gangloff says. o this intuition for how to arrange atoms so as to minimize
or maximize friction could be applied. Tobias Schaetz, a professor of physics at the University of Freiburg in Germany, sees the results as a lear breakthroughin gaining insight into therwise inaccessible fundamental physics.
which are an atom thick and about 10,000 times smaller than a human hair in diameter, in the membrane pores.
and some nanomaterials are only a few atoms in size. The method described in the Scientific Reports article tructural color printing based on plasmonic metasurfaces of perfect light absorptioninvolves the use of thin sandwiches of nanometer scale metal-dielectric materials known as metamaterials that interact with light
-and at its ultimate size limit-one atom thick.""The team is currently analysing and characterising the performance of the devices, including the time taken to turn on
#Chemists Witness Atoms of One Chemical element Morph Into Another The research appears in Nature Materials, June 15, 2015, online in advance of print.
which can produce images of each atom in a material surface, they observed individual atoms of iodine-125 decay.
As each atom decayed it lost a proton and became tellurium-125, a nonradioactive isotope of the element tellurium.
The transformation of one element to another occurred when the researchers infused a single droplet of water with iodine-125
When the water evaporated, the iodine atoms bonded with the gold. The researchers inserted the tiny samplemaller than a dimento the microscope.
Iodine-125 atoms have a half-life of 59 days, meaning that at any time, any atom of the radioisotope will decay,
giving off vast amounts of energy and becoming the isotope of tellurium, with half of the atoms decaying every 59 days.
It was impossible to predict when any one of the trillions of atoms in the sample would transmute into tellurium,
so the researchers worked up to 18 hours a day for several weeks so they wouldn miss the transformations.
Eventually they managed to take scanning tunneling microscope images that showed small atom-sized spots all over the surface.
and assign the features as newly formed tellurium atoms. To verify that they had seen indeed the transformation,
the team has unveiled how fluids behave under extreme confinement by using micron-sized particles known as colloids to act as oversized atoms.
Atoms are tiny and cannot be seen under a microscope. This is not the same for colloidal particles,
and that is our world we can control cellulose-based materials one atom at a time. The Hinestroza group has turned cotton fibers into electronic components such as transistors and thermistors
San diego graduate student has found a way to use mass-produced graphene, an allotrope of carbon that is one atom-thick.
and it 200 times stronger than steel because of the way the atoms bond to form a hexagonal pattern (think of chicken wire) with a cloud of free electrons hovering above and below it,
This collision produces lithium-8 atoms which are ionized and slowed down to a desired energy level before they are implanted in the topological insulators.
In betaetected nuclear magnetic resonance, ions (in this case, the ionized lithium-8 atoms) of various energies are implanted in the material of interest (the topological insulator) to generate signals from the material layers of interest.
This in depth information allowed the research team to gain new insights into the growth of these highly useful particles at individual atom level.
arranging atoms to achieve more potent chemical reactions while using less material. In a paper to be published July 24 in the journal Science
the researchers describe how they teased a small number of platinum atoms into hollow"cage"structures that prove to be 5. 5 times as potent as conventional platinum non-hollowed particles in an oxygen-reduction reaction crucial
then deposit a few layers of platinum atoms on top of it. Calculations by Mavrikakis'group show that platinum atoms have a tendency to burrow into the palladium during the deposition.
This allows the palladium to be removed by etching agents, leaving behind a cagelike structure in the initial shape of the palladium template with faces formed by layers of platinum just three to five atoms thick.
Reactants can flow into the hollow structure through holes in the faces interacting with more platinum atoms in the chemical reaction than would be the case on a flat sheet of platinum or traditional, nonhollowed nanoparticles."
"Because of this new structure they're taking on, they're naturally shortening the distances between platinum atoms,
which makes the platinum more active for the oxygen reduction reaction, "says Luke Roling, a graduate student in Mavrikakis'lab."We're also able to use more of the platinum atoms than we were before--at best,
you could get up to twice as much of your platinum exposed.""Mavrikakis points out that, in a scaled-up version of this process,
it would be possible to reuse palladium atoms after etching agents remove them from the nanoparticle.
or more layers--it's harder to remove the palladium atoms and obtain the desired hollowed cages.
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