Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: particle physics

Quantum entanglement – that strange but potentially hugely useful quantum phenomenon where two particles are inextricably linked across space and time – could play a major role in future radar technology.

In 2008, an engineer from MIT devised a way to use the features of entanglement to illuminate objects while using barely any photons. In certain scenarios, such technology promises to outperform conventional radar, according to its makers, particularly in noisy thermal environments.

Now, researchers have taken the idea much further, demonstrating its potential with a working prototype.

Read more | >

Quantum entanglement is a process by which microscopic objects like electrons or atoms lose their individuality to become better coordinated with each other. Entanglement is at the heart of quantum technologies that promise large advances in computing, communications and sensing, for example, detecting gravitational waves.

Entangled states are famously fragile: In most cases, even a tiny disturbance will undo the entanglement. For this reason, current quantum technologies take great pains to isolate the microscopic systems they work with, and typically operate at temperatures close to absolute zero. The ICFO team, in contrast, heated a collection of atoms to 450 Kelvin in a recent experiment, millions of times hotter than most atoms used for quantum technology. Moreover, the were anything but isolated; they collided with each other every few microseconds, and each collision set their electrons spinning in random directions.

The researchers used a laser to monitor the magnetization of this hot, chaotic gas. The magnetization is caused by the spinning electrons in the atoms, and provides a way to study the effect of the collisions and to detect entanglement. What the researchers observed was an enormous number of entangled atoms—about 100 times more than ever before observed. They also saw that the entanglement is non-local—it involves atoms that are not close to each other. Between any two entangled atoms there are thousands of other atoms, many of which are entangled with still other atoms, in a giant, hot and messy entangled state.

Read more | >

Almost a millennium ago, a major upheaval occurred in Earth’s atmosphere: a giant cloud of sulphur-rich particles flowed throughout the stratosphere, turning skies dark for months or even years, before ultimately falling down to Earth.

We know this event happened because researchers have drilled and analysed ice cores — samples taken from deep within ice sheets or glaciers, which have trapped sulphur aerosols produced by volcanic eruptions reaching the stratosphere and settling back on the surface.

Ice can thus preserve evidence of volcanism over incredibly long timescales, but pinpointing the precise date of an event that shows up in the layers of an ice core is still tricky business.

Read more | >

Quantum entanglement is a process by which microscopic objects like electrons or atoms lose their individuality to become better coordinated with each other. Entanglement is at the heart of quantum technologies that promise large advances in computing, communications and sensing, for example detecting gravitational waves.

Entangled states are famously fragile: in most cases even a tiny disturbance will undo the entanglement. For this reason, current quantum technologies take great pains to isolate the microscopic systems they work with, and typically operate at temperatures close to absolute zero. The ICFO team, in contrast, heated a collection of atoms to 450 Kelvin, millions of times hotter than most atoms used for quantum technology. Moreover, the individual atoms were anything but isolated; they collided with each other every few microseconds, and each collision set their electrons spinning in random directions.

The researchers used a laser to monitor the magnetization of this hot, chaotic gas. The magnetization is caused by the spinning electrons in the atoms, and provides a way to study the effect of the collisions and to detect entanglement. What the researchers observed was an enormous number of entangled atoms — about 100 times more than ever before observed. They also saw that the entanglement is non-local — it involves atoms that are not close to each other. Between any two entangled atoms there are thousands of other atoms, many of which are entangled with still other atoms, in a giant, hot and messy entangled state.

Read more | >

Circa 2017

Einstein-Rosen or “ER” bridges, are equivalent to entangled quantum particles, also known as Einstein-Podolsky-Rosen or “EPR” pairs. The quantum connection between wormholes prevents their collapse without involving exotic matter.

The quantum-teleportation format precludes using these traversable wormholes as time machines. Anything that goes through the wormhole has to wait for Alice’s message to travel to Bob in the outside universe before it can exit Bob’s black hole, so the wormhole doesn’t offer any superluminal boost that could be exploited for time travel.

Researchers are working towards lab tests of quantum teleportation to verify their theories.

Read more | >

Physicists have measured the flight times of electrons emitted from a specific atom in a molecule upon excitation with laser light. This has enabled them to measure the influence of the molecule itself on the kinetics of emission.

Photoemission—the release of electrons in response to excitation by light—is one of the most fundamental processes in the microcosm. The kinetic energy of the emitted electron is characteristic for the atom concerned, and depends on the wavelength of the light employed. But how long does the process take? And does it always take the same amount of time, irrespective of whether the electron is emitted from an individual atom or from an atom that is part of a molecule? An international team of researchers led by laser physicists in the Laboratory for Attosecond Physics (LAP) at LMU Munich and the Max Planck Institute of Quantum Optics (MPQ) in Garching has now probed the influence of the molecule on photoemission time.

The theoretical description of photoemission in 1905 by Albert Einstein marked a breakthrough in , and the details of the process are of continuing interest in the world of science and beyond. How the motions of an elementary quantum particle such as the electron are affected within a molecular environment has a significant bearing on our understanding of the process of photoemission and the forces that hold molecules together.

Read more | >

O,.,o.

The weird world of quantum physics is being harnessed for some fascinating use cases. In the latest example, physicists have developed and demonstrated a “quantum radar” prototype that uses the quantum entanglement phenomenon to detect objects, a system which could eventually outperform conventional radar in some circumstances.

Quantum entanglement describes the bizarre state where two particles can become linked so tightly that they seem to communicate instantly, no matter how far apart they are. Measuring the state of one particle will instantly change the state of the other, hypothetically even if it’s on the other side of the universe. That implies that the information is moving faster than the speed of light, which is thought to be impossible – and yet, it’s clearly and measurably happening. The phenomenon even unnerved Einstein himself, who famously described it as “spooky action at a distance.”

While we still don’t entirely understand why or how it works, that’s not stopping scientists figuring out ways to use it to our advantage. Strides are being made towards creating quantum computers and a quantum internet, both of which would be super fast and nigh-unhackable. And now, in a new study by physicists at the Institute of Science and Technology Austria (IST Austria), MIT and the University of York, the phenomenon been applied to radar.

Read more | >

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object’s wake, greatly reducing its drag while simultaneously helping it avoid detection.

The idea originated at Duke University in 2011 when researchers outlined the general concept. By matching the acceleration of the surrounding water to an ’s movement, it would theoretically be possible to greatly increase its propulsion efficiency while leaving the surrounding sea undisturbed. The theory was an extension of the group’s pioneering work in metamaterials, where a material’s structure, rather than its chemistry, creates desired properties.

Six years later, Yaroslav Urzhumov, adjunct assistant professor of electrical and computer engineering at Duke, has updated the theory by detailing a potential approach. But rather than using a complex system of very small pumps as originally speculated, Urzhumov is turning to electromagnetic fields and the dense concentration of charged particles found in saltwater.

Read more | >

Linking multiple copies of these devices may lay the foundation for quantum computing.

Once unimaginable, transistors consisting only of several- atom clusters or even single atoms promise to become the building blocks of a new generation of computers with unparalleled memory and processing power. But to realize the full potential of these tiny transistors — miniature electrical on-off switches — researchers must find a way to make many copies of these notoriously difficult-to-fabricate components.

Now, researchers at the National Institute of Standards and Technology (NIST) and their colleagues at the University of Maryland have developed a step-by-step recipe to produce the atomic-scale devices. Using these instructions, the NIST-led team has become only the second in the world to construct a single-atom transistor and the first to fabricate a series of single electron transistors with atom-scale control over the devices’ geometry.

Read more | >