How to Bend A Diamond

by Adwaith.B.S(2016-2019)

adwaithbalachandran123@gmail.com

 

Diamond is the hardest natural material, but now scientists have shown that it can bend and stretch, much like rubber, and even elastically snap back into shape — even if it only happens with diamonds that are very small. Such flexibility could open up a wide new range of applications for diamond, the researchers say.

Diamond is extraordinarily hard, meaning it excels at resisting any change to its shape — that’s why a diamond can cut through softer materials and will only be scratched by another diamond. However, diamond is not especially tough — when enough force is applied to it to change its shape, it doesn’t usually bend, it breaks.

Bend Like A Diamond

Still, previous research found that, in theory, the diamond should be able to flex a bit. The key was to create pure crystals of diamond without any microscopic flaws or variations that would make them brittle.

An international team of researchers took thin films of artificial diamonds and etched out needles just 300 nanometers, or billionths of a meter, long.. They next pressed down on these slivers with a diamond probe and watched what happened using a scanning electron microscope.

The scientists found their diamond needles could bend and stretch by up to 9 percent without breaking and rebound back to their original shape after the pressure was removed. These results approach what the research team’s computer models suggested was the diamond’s theoretical limit of flexibility. By contrast, an ordinary diamond in bulk form breaks well below strain levels of even 1 percent.

“The hardest natural material, diamond, which is commonly believed to be undeformable, can be bent and stretched significantly,” said study co-senior author Yang Lu, a materials scientist and mechanical engineer at the City University of Hong Kong. “A diamond needle could be severely bent almost 30 degrees and, more importantly, fully recover.”

Mind-bending

The unexpected improved durability of diamond could lead to many new applications. For instance, robust and cost-effective microscopic diamond needles could help deliver genes or drugs into cells, Lu said.

In addition, when a diamond is flexed, it could stretch and squeeze the molecular bonds in ways that could significantly alter its electronic, thermal, optical, magnetic and chemical properties, said study co-senior author Subra Suresh, president of Singapore’s Nanyang Technological University. The researchers suggested that further experiments flexing diamond might discover new behaviors for novel applications, “such as a more powerful or colorful laser or maser,” Lu said.

Controlling how sensitive diamonds are to magnetic fields could also have a variety of sensor applications, said study co-senior author Ming Dao, a materials scientist and mechanical engineer at MIT. For example, a diamond with altered magnetic properties could find use in magnetic resonance imaging (MRI) scans.

The scientists detailed their findings in the April 20 issue of the journal Science.

Quantum weirdness in ‘chicken or egg’ paradox

by Adwaith.B.S(2016-2019)

adwaithbalachandran123@gmail.com

Source:

 University of Queensland 

 

The “chicken or egg” paradox was first proposed by philosophers in Ancient Greece to describe the problem of determining cause-and-effect.  

 Now, a team of physicists from The University of Queensland and the NÉEL Institute has shown that, as far as quantum physics is concerned, the chicken and the egg can both come first.Dr. Jacqui Romero from the ARC Centre of Excellence for Engineered Quantum Systems said that in quantum physics, cause-and-effect is not always as straightforward as one event causing another.

“The weirdness of quantum mechanics means that events can happen without a set order,” she said.

“Take the example of your daily trip to work, where you travel partly by bus and partly by train.

“Normally, you would take the bus then the train, or the other way round.

“In our experiment, both of these events can happen first,” Dr. Romero said.

“This is called `indefinite causal order’ and it isn’t something that we can observe in our everyday life.”

To observe this effect in the lab, the researchers used a setup called a photonic quantum switch.

UQ’s Dr. Fabio Costa said that with this device the order of events — transformations on the shape of light — depends on polarisation.

“By measuring the polarisation of the photons at the output of the quantum switch, we were able to show the order of transformations on the shape of light was not set.”

“This is just a first proof of principle, but on a larger scale indefinite causal order can have real practical applications, like making computers more efficient or improving communication.”
The research was published in Physical Reviews Letters by the American Physical Society.

Equinox Explained: Why Earth’s Seasons Will Change on Sunday

by Sidhi.S.L.Nair(2016-2019)

Sidnair017@gmail.com

The seasons will change this Sunday (Sept. 22), with the Northern Hemisphere moving into autumn and the South emerging from winter into spring.

The celestial event that marks this transition is called an “equinox,” and it happens twice every year, around March 21 and Sept. 21. Just what is an equinox, and why does it occur?

The Earth moves in two different ways. First, the planet spins on its polar axis — a line through the north and south poles — once every 24 hours, causing the alternation of day and night. Secondly, it moves in its orbit around the sun once every 365.25 days, causing the annual cycle of seasons. The equinox occurs when these two motions intersect.

Because the Earth is so big, its mass has an enormously powerful gyroscopic effect. For this reason, its poles always point in the same direction, although a major earthquake can cause tiny wobbles in this axis. Most importantly, the Earth’s motion around the sun has absolutely no effect on the direction the poles are pointing, which has very important consequences for Earth Seasons.

Astronomers mark the positions of objects in the sky relative to the Earth’s poles of rotation (those are the red lines you see in the picture). The most important line is the celestial equator, which divides the sky into the Northern and Southern Hemispheres.

The Earth’s pole of rotation is tilted 23.4 degrees relative to the plane of its orbit. This tilt is always toward the same point in the sky, called the celestial pole, no matter where in its orbit around the sun the Earth happens to be.

This tilt makes it appear to observers on Earth’s surface that the sun is moving across the sky at an angle to the celestial equator. This is marked by the green line in the image, called the “ecliptic” because eclipses happen along this line.

Twice a year, the sun crosses the celestial equator, moving from the Northern Hemisphere to the Southern Hemisphere, or vice versa. These two crossings are very important for the inhabitants of Earth, because they mark the change in the direction the sun’s rays fall on Earth.

Specifically, on Sunday, the sun will move from the Northern Hemisphere to the Southern Hemisphere. It will pass overhead everywhere along the Earth’s equator on that date, and the sun will rise exactly in the east and set exactly in the west. Day and night will also be of roughly equal length. (“Equinox” is derived from the Latin for “equal night.”)

After Sunday, the sun will shine more on the southern half of our planet and less on the northern half. Summer will be over in the Northern Hemisphere, and fall will have arrived. Winter will be over in the south, and spring will begin.

The sun will continue on its path southward for the next three months, reaching its southernmost point on Dec. 21, the date of the “solstice.” In the Northern Hemisphere, the days will become shorter, the nights longer, and the temperatures colder during this three-month trek, all as a result of the sun’s being south of the celestial equator.

 

It’s always important to remember that this is part of a cycle, and that after Dec. 21 the sun will start moving northward again, and spring will be on its way.

 

Scientists ‘teleport’ a quantum gate

by Abhijith.A.D(2016-2019)

https://www.facebook.com/abhijith.vjmd

Date:

 September 5, 2018

Source:

 Yale University

Summary:

 Researchers have demonstrated one of the key steps in building the architecture for modular quantum computers: the ‘teleportation’ of a quantum gate between two qubits, on demand.

 

Yale University researchers have demonstrated one of the key steps in building the architecture for modular quantum computers: the “teleportation” of a quantum gate between two qubits, on demand.

The key principle behind this new work is quantum teleportation, a unique feature of quantum mechanics that has previously been used to transmit unknown quantum states between two parties without physically sending the state itself. Using a theoretical protocol developed in the 1990s, Yale researchers experimentally demonstrated a quantum operation, or “gate,” without relying on any direct interaction. Such gates are necessary for quantum computation that relies on networks of separate quantum systems — an architecture that many researchers say can offset the errors that are inherent in quantum computing processors.

Through the Yale Quantum Institute, a Yale research team led by principal investigator Robert Schoelkopf and former graduate student Kevin Chou is investigating a modular approach to quantum computing. Modularity, which is found in everything from the organization of a biological cell to the network of engines in the latest SpaceX rocket, has proved to be a powerful strategy for building large, complex systems, the researchers say. A quantum modular architecture consists of a collection of modules that function as small quantum processors connected into a larger network.

Modules in this architecture have a natural isolation from each other, which reduces unwanted interactions through the larger system. Yet this isolation also makes performing operations between modules a distinct challenge, according to the researchers. Teleported gates are a way to implement inter-module operations.

“Our work is the first time that this protocol has been demonstrated where the classical communication occurs in real-time, allowing us to implement a ‘deterministic’ operation that performs the desired operation every time,” Chou said.

Fully useful quantum computers have the potential to reach computation speeds that are orders of magnitude faster than today’s supercomputers. Yale researchers are at the forefront of efforts to develop the first fully useful quantum computers and have done pioneering work in quantum computing with superconducting circuits.

Quantum calculations are done via delicate bits of data called qubits, which are prone to errors. In experimental quantum systems, “logical” qubits are monitored by “ancillary” qubits in order to detect and correct errors immediately. “Our experiment is also the first demonstration of a two-qubit operation between logical qubits,” Schoelkopf said. “It is a milestone toward quantum information processing using error-correctable qubits.”