Sunlight to electricity Solar cells work by converting photons of sunlight into an electric current that moves between two electrodes.
Silicon solar cells generate electricity by absorbing photons of visible and infrared light, while perovskite cells harvest only the visible part of the solar spectrum where the photons have more energy.
Microscopic cross-section of a tandem solar cell made with two photovoltaic materials, perovskite stacked on top of CIGS (copper indium gallium diselenide).
Colin Bailie, Stanford bsorbing the high-energy part of the spectrum allows perovskite solar cells to generate more power per photon of visible light than silicon cells,
so that some photons could penetrate the perovskite layer and be absorbed by the silicon at the bottom,
But the graphene retains its ability to move electrons quickly and gives it the quick charge
##Single-photon emission enhancement#seen as step toward quantum technologies Researchers have demonstrated a new way to enhance the emission of single photons by using yperbolic metamaterials,
Optical metamaterials harness clouds of electrons called surface plasmons to manipulate and control light. Purdue University researchers had created previously uperlatticesfrom layers of the metal titanium nitride and the dielectric,
In new findings the researchers have demonstrated how attaching nanodiamonds containing itrogen-vacancy centersto the new metamaterial further enhances the production of single photons, workhorses of quantum information processing,
cryptography and communications technologies. hese results indicate that the brightness of the nanodiamond-based single-photon emitter could be enhanced substantially by placing such an emitter on the surface of the hyperbolic metamaterial,
associate professor of electrical and computer engineering at Purdue. he single-photon emitters could be used to build highly efficient room temperature CMOS-compatible single-photon sources.
Placing a nanodiamond containing an NV center on the surface of hyperbolic metamaterials not only enhances the emission of photons,
Because the studied system represents a stable source of single photons that functions at room temperature
which causes it to spontaneously emit a photon. e are interested in causing it to emit faster
so that we can increase the rate of these photons coming out, Kildishev said. Findings show the system is capable of producing single photons faster, in larger quantities,
and more directionally. Metamaterials have engineered surfaces that contain features, patterns or elements, such as tiny antennas or alternating layers of nitrides that enable unprecedented control of light.
The nitrogen vacancy also makes it possible to potentially record information based on the nuclear or electron pinstate of the center,
because the sulphur dissolves into the electrolyte solution as it reduced by incoming electrons to form polysulphides.
and introducing quantum wells to control the movement of electrons, new possibilities for graphene based optoelectronics have now been realised.
the quantum efficiency (photons emitted per electron injected) is already comparable to organic LEDS. Source: University of Mancheste
They can rip electrons away from their atoms they can accelerate electrons they can help to monitor the dynamics of chemical reactions.
Depending on the exact shape of the laser pulse the electrons ripped away from the xenon atoms can be sent into different directions. t is an ultrafast electron switchsays Tadas Balciunas.
which photons transmit information about those atomselectronic spin states, which can be used to store quantum information.
Such spin-photon interfaces are thought to be essential for connecting distant quantum memories, which could open the door to quantum computers and long-distance cryptographic systems.
Photons that enter these nanoscale funhouses bounce back and forth up to 10 000 times, greatly enhancing their chance of interacting with the electrons in the NV center.
Crucially, the team demonstrated a spin-coherence time (how long the memory encoded in the electron spin state lasts) of more than 200 microseconds long time in the context of the rate at
which computational operations take place. A long coherence time is essential for quantum computing systems and long-range cryptographic networks. ur research demonstrates a technique to extend the storage time of quantum memories in solids that are coupled efficiently to photons,
which is essential to scaling up such quantum memories for functional quantum computing systems and networks, said MIT Dirk Englund,
and characterize the materials. he memory elements described in this research are the spin states of electrons in nitrogen-vacancy (NV) centers in diamond.
The up or down orientation of the electron spins on these NV centers can be used to encode information in a way that is somewhat analogous to how the charge of many electrons is used to encode the and in a classical computer.
scientists can manipulate the electron spins into or back into using microwaves. The state has brighter fluorescence than the state,
The trick is getting the electron spins in the NV centers to hold onto the stable spin states long enough to perform these logic gate operationsnd being able to transfer information among the individual memory elements to create actual computing networks
. t is already possible to transfer information about the electron spin state via photons but we have to make the interface between the photons and electrons more efficient.
The trouble is that photons and electrons normally interact only very weakly. To increase the interaction between photons and the NV,
we build an optical cavity trap for photonsround the NV, Englund said. These cavities, nanofabricated at Brookhaven by MIT graduate student Luozhou Li with the help of staff scientist Ming Lu of the CFN, consist of layers of diamond
and air tightly spaced around the impurity atom of an NV center. At each interface between the layers there a little bit of reflectionike the reflections from a glass surface.
With each layer the reflections add upike the reflections in a funhouse filled with mirrors.
Photons that enter these nanoscale funhouses bounce back and forth up to 10,000 times, greatly enhancing their chance of interacting with the electrons in the NV center.
This increases the efficiency of information transfer between photons and the NV center electron spin state.
The devicesperformance was characterized in part using optical microscopy in a magnetic field at the CFN, performed by CFN staff scientist Mircea Cotlet, Luozhou Li,
hese methods have given us a great starting point for translating information between the spin states of the electrons among multiple NV centers.
he transferred hard mask lithography technique that we have developed in this work would benefit most unconventional substrates that aren suitable for typical high-resolution patterning by electron beam lithography.
and shuttle data with light instead of electrons. Electrical and computer engineering associate professor Rajesh Menon and colleagues describe their invention today in the journal Nature Photonics.
or shuttled is done through light instead of electrons. Image credit: Dan Hixson/University of Utah College of Engineeringsilicon photonics could significantly increase the power and speed of machines such as supercomputers, data center servers and the specialized computers that direct autonomous cars and drones with collision detection.
says Menon. ut that information has to be converted to electrons when it comes into your laptop.
Photons of light carry information over the Internet through fiber-optic networks. But once a data stream reaches a home or office destination
the photons of light must be converted to electrons before a router or computer can handle the information.
And because photonic chips shuttle photons instead of electrons mobile devices such as smartphones or tablets built with this technology would consume less power,
and the redox reactions in which the electrons are transferred between electrodes also occur at very high rates in this particular battery.
#Researchers Discover Electron Pairing without Superconductivity A team of physicists from the University of Pittsburgh, the University of Wisconsin-Madison,
and the U s. Naval Research Laboratory (NRL) has discovered electron pairing in strontium titanate far above the superconducting transition temperature.
which electrons form pairs that do not condense into a superconducting phase. The complete findings are published in the May 14,
The basis for all superconductors is the formation of electron pairs. In the normal non-superconducting phase, the electrons in most metals move independentlyhe scattering of electrons causes electrical resistance.
In a superconductor, the paired electrons move in a highly coordinated fashion that has zero electrical resistance.
The new research identified an intermediate phase in which electrons form pairs, but the pairs move independently.
The independent pairs are able to scatter, and the phase exhibits electrical resistance. The researchers used quantum dots in strontium titanate to observe the electron pairs.
Quantum dots are small regions of a material in which the number of electrons can be controlled precisely,
in this case using an electrostatic gate. The quantum dots were large enough to support a superconducting phase at low temperatures
but the researchers observed that the dots always preferred an even number of electrons in the new phase at higher temperatures.
they observed breaking of the electron pairs one at a time. A theory of electron pairing without formation of a superconducting state was published first by David M. Eagles in 1969.
C. Stephen Hellberg, a physicist in NRL Material Science and Technology Division and the team theorist, observed he results are described well by a simple model with attractive interactions between electrons.
We still don know the origin of the attractive interaction: possibilities include egative-Udefect centers and bipolarons.
These images show differential conductance through the quantum dot as a function of the gate voltage that controls the number of electrons in the dot (x-axis) and the applied magnetic field (y-axis).
) Blue regions have low differential conductance and a constant number of electrons; green, yellow, and brown show higher differential conductance, indicating a change in the number of electrons in the dot.
The top panel shows the measured differential conductance; the bottom panel shows the theoretical calculation (which has no disorder.
Both experiment and theory show splitting of the electron pairs with increasing field and reentrant pairing at higher fields (the merging of pairs of boundaries into vertical boundaries) l
This is necessary because materials are susceptible to being destroyed by the high energy electron beam that is used to image them.
Silicene great promise is related to how electrons can streak across it at incredible speed close to the speed of light.
Propelling the electrons in silicene requires minimal energy input, which means reducing power and cooling requirements for electronic devices. f silicene could be used to build electronic devices,
This current of heat creates a separation of electron spins that then diffuse through the Cu heat sink and affect the magnetization of a second ferromagnetic layer,
Spin transfer torque is the transfer of the spin angular momentum from conduction electrons to the magnetization of a ferromagnet
The spin-dependent Seebeck effect refers to the analogous phenomenon involving the spin of electrons in a ferromagnet.
Unlike most of the commercially available detectors, RAPID can spot photons (light particles) of both visible and infrared light (wavelengths from 0. 4. 6 micrometres.
the increased spectral coverage means that far more photons can be gathered, especially from infrared wavelengths, where many objects shine most brilliantly.
Every photon arriving into the detector is converted into many more than one electron, therefore easing its detection.
In photosynthesis, plants that are exposed to sunlight use carefully organized nanoscale structures within their cells to rapidly separate charges pulling electrons away from the positively charged molecule that is left behind,
The polymer donor absorbs sunlight and passes electrons to the fullerene acceptor; the process generates electrical energy.
because the electrons sometimes hop back to the polymer spaghetti and are lost. The UCLA technology arranges the elements more neatly like small bundles of uncooked spaghetti with precisely placed meatballs.
The fullerenes inside the structure take electrons from the polymers and toss them to the outside fullerene
which can effectively keep the electrons away from the polymer for weeks. hen the charges never come back together,
allowing electrons to flow through it and that the conductivity of that DNA wire is extremely sensitive to mistakes in the DNA itself.
Including electron spin as an additional state variable offers new prospects for information processing, enabling future nonvolatile, reprogrammable devices beyond the current semiconductor technology roadmap.
But curvature in graphene compresses the electron clouds of the bonds on the concave side and stretches them on the convex side,
which electrons are bound inside complex oxides means that any strain stretching, pulling or pushing of the structure triggers changes in many different electronic properties.
which devices work by manipulating the quantum mechanical spin1 of electrons, in addition to their elementary electric charge.
Just as conventional transistors have a source of electrons, a gate to control their movement, and a drain to carry off the charge signal,
a spintronic circuit needs a well-controlled source of spin-polarized electrons that are injected into a transport channel material,
Compared to manipulating populations of moving electrons through a conventional semiconductor, controlling electron spins consumes much less energy
and has the further advantage that its information content is on-volatile because the information is moved
Spin-polarized electrons are predicted to have long lifetimes in organic semiconductors; Spin-based devices integrated with organic materials are expected to have low fabrication costs, light weight, and mechanical flexibility;
and an organic semiconductor known as Alq3 can be altered by coating the cobalt with a single-molecule thick layer (monolayer) that affects the electron spin states of the cobalt.
instead depends upon the uncanny ability of gold atoms to trap silicon-carrying electrons to selectively prevent the etching.
and could be important for future device technologies as well as for fundamental studies of electron transport in molecular nanostructures.
In atomic-scale transistors, this current is extremely sensitive to single electrons hopping via discrete energy levels.
In earlier studies, researchers have examined single-electron transport in molecular transistors using top-down approaches, such as lithography and break junctions.
single electrons can tunnel between template and tip by hopping via nearly unperturbed molecular orbitals,
In our case, the charged atoms nearby provide the electrostatic gate potential that regulates the electron flow
and orientation has a dramatic effect on the electron flow across the molecule, manifested by a large conductance gap at low bias voltages.
The patent-pending technology is created by 3d Tau. Features of 3d Tau Stereo-Step-Eclipse Technology:
Easy to use: No special glasses, helmets or head tracking are needed and there no need to perform dynamic adaptation for any particular viewer.
3d Tau enables any number of viewers, arrayed at any angle, to see the 3d image on the screen.
remote medicine and a wide variety of other business, civil and military uses. 3d Tau SSE technology is designed to be embedded directly into a new generation of screens for televisions, movie theaters, computer displays, game
Other applications that can benefit from the 3d Tau SSE technology include the display of topographical maps,
The 3d Tau SSE technology can also be used to allow different viewers of a single screen to view different content based on their viewing angle.
But quarks are even smaller particleshe building blocks of protons, neutrons and other subatomic particles known as baryons.
and neutrons, are composed of three quarks. A pentaquark is something different omposite statethat groups four quarks and one antiquark
the associated antimatter particle for a quark. Studying composite states can give scientists additional insight into the properties of ordinary baryons. enefitting from the large data set provided by the LHC,
and the excellent precision of our detector, we have examined all possibilities for these signals, and conclude that they can only be explained by pentaquark states,
whose research group was a leader in the analysis. ore precisely the states must be formed of two up quarks, one down quark, one charm quark and one anti-charm quark.
The discovery was made by the CERN Large hadron collider b-quark (LHCB) experiment group one of several ongoing particle physics experiments at the laboratory.
said LHCB spokesperson Guy Wilkinson. t represents a way to aggregate quarks, namely the fundamental constituents of ordinary protons and neutrons, in a pattern that has never been observed before in over fifty years of experimental searches.
known as Lambda b. hile existence of pentaquarks was speculated on since the beginning of the quark model in 1964,
and will lead to a better understanding of quark formations created by nuclear forces, with possible implications in astrophysics.
exactly, quarks are bound together in pentaquarksoosely or tightly. The answer to that question will play a key role in determining
The team electron spin resonance (ESR) probe takes a large-scale technique used for decades as a way to explore the overall properties of bulk materials
and recombining negatively charged electrons with their positively charged oles, which ideally produce electric current by migrating in opposite directions following their separation by photon-carrying sunlight.
Lead author Jinsong Huang and his team sought to reduce the number of these efficiency-draining barriers by increasing the size of the grains themselves.
said Hofmann. t a flexible platform that can be used for different technologies. ossible applications for this technique range from atomically perfect buried interconnects to single-electron transistors, high-density memories, light emission, semiconductor lasers,
low-power electronics that use electron spin rather than charge to carry information. Wu work upends prevailing ideas of how to generate a current of spins. his is a discovery in the true sense
Spin is a quantum property of electrons that scientists often compare to a tiny bar magnet that points either por own.
One such method is to separate the flow of electron spin from the flow of electron current
scientists have kept typically electrons stationary in a lattice made of an insulating ferromagnetic material, such as yttrium iron garnet (YIG).
the resulting increase in length and decrease in cross-sectional area restricts the flow of electrons through the material.
because electrons can travel over such a hierarchically buckled sheath as easily as they can traverse a straight sheath.
At its most basic level, your smart phone battery is powering billions of transistors using electrons to flip on and off billions of times per second.
But if microchips could use photons instead of electrons to process and transmit data, computers could operate even faster.
the free electrons on its surface begin to oscillate together in a wave. These oscillations create their own light,
which reacts again with the free electrons. Energy trapped on the surface of the nanocube in this fashion is called a plasmon.
The quantum dots, in turn, produce a directional, efficient emission of photons that can be turned on and off at more than 90 gigahertz. here is great interest in replacing lasers with LEDS for short-distance optical communication,
lack of efficiency and inability to direct the photons, said Gleb Akselrod, a postdoctoral research in Mikkelsen laboratory. ow we have made an important step towards solving these problems. n illustration of the new superfast fluorescent system.
is pushing pretty hard for. he group is now working to use the plasmonic structure to create a single photon source necessity for extremely secure quantum communicationsy sandwiching a single quantum dot in the gap between the silver nanocube and gold foil.
For the present demonstration, the researchers had to use a laser light to pump electrons to emit light.
probably because ammonia donates electrons that neutralize holes in the black phosphorus sheets. That immediately makes black phosphorous a decent ammonia detector.
It's called the Weyl fermion. Originally proposed by mathematician Hermann Weyl in 1929, these fermions are thought to be the building blocks of other subatomic particles.
Right now, electricity is carried by streams of electrons -but Weyl fermions could provide a much more stable and efficient way of doing the same thing.
One interesting quirk of their physics is that they can behave as a composite of matter and antimatter inside a crystal
-which is how they were found, and the only place they can exist. But another is that they can be used to create massless electrons that move very quickly
and aren't lost as heat energy when they collide with something like regular electrons do.""It's like they have their own GPS
and steer themselves without scattering,"said M. Zahid Hasan, who led the research team.""These are very fast electrons that behave like unidirectional light beams
and can be used for new types of quantum computing.""He added:""The physics of the Weyl fermion are so strange,
there could be many things that arise from this particle that we're just not capable of imagining now."
However, so far only electron holography could be considered for mapping magnetic domains of three-dimensional objects at the nanometre scale
and control the electron flow through the gate. Typically scientists working to this atomic scale have struggled to reliably control the flow of electrons
which are difficult to contain and can jump outside of the transistor, rendering it useless.
said that researchers had created the smallest laser possible powered by single electrons that burrow through quantum dots.
"is a minuscule microwave laser that demonstrates how light and moving electrons interact with each other, said Princeton university.
who worked with Petta in his lab. Prof Petta added that a double quantum dot was capable of only transferring one electron at a time.
These double quantum dots are zero-dimensional as far as the electrons are concerned they are trapped in all three spatial dimensions.
The team found that electrons would travel through the graphene as well as through the copper wire,
For this study, the researchers had to pump electrons into the semiconductors with an additional laser light.
#Princeton Researchers Develop Rice Sized Laser Princeton university researchers have built a rice sized laser powered by single electrons tunneling through artificial atoms known as quantum dots.
They found that the electrons flowed in a single-file through each dot, which emitted photons in the microwave region of the light spectrum.
The photons bounced off mirrors on either side of the cavity, creating a beam of microwave light. e designed dots to emit photons
when single electrons jump from a higher to a lower energy level across the double dot.
It is like a line of people crossing a wide stream by leaping onto a rock so small that it can only hold one person.
They are forced to cross the stream one at a time. These double quantum dots are zero-dimensional as far as the electrons are concerned they are trapped in all three spatial dimensions
explained Jason Petta, an associate professor of physics at Princeton university and leader of the study. The findings were published in the Science journal e
rice grain sized laser that is powered by a single electron from the artificial atoms called quantum dots.
said, t is basically as small as you can go with these single-electron devices. The discovery will boost the ongoing efforts of scientists across the world to use semiconductor materials to build quantum computing systems. consider this to be a really important result for our long-term goal,
Qubits are the basic unit of information in quantum computing. e designed dots to emit photons
when single electrons jump from a higher to a lower energy level across the double dot.
These double quantum dots are zero-dimensional as far as the electrons are concerned they are trapped in all three spatial dimensions,
A single electron trapped in a semiconductor nanostructure can form the most basic of building blocks for a quantum computer.
scientists need to develop a scalable architecture that allows full control over individual electrons in computational arrays.
This will help physicists in their understanding of the behavior between elementary particles. The existence of these particles was known theoretically,
They are made up of three even tinier building blocks, called quarks. Together in different combinations, quarks construct a different baryon each time.
The two new particles that were discovered recently have the same quarks but with different configurations.
The new particles are also positively charged (similar to protons) and six times larger than a proton.
The previous phone was the Motorola Photon Q, an Android phone that sold for $269.
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