When one atom emits light, they do so in a separate package called a photon. When this light is measured, this discrete or granular nature leads to small brightness fluctuations because two or more photons never emit simultaneously.
Category: particle physics – Page 542
The military’s future body armor could be as thin as 2 atoms
If you’ve been a grunt, then you probably have a love-hate relationship with body armor. You love having it in a firefight — it can save your life by stopping or slowing bullets and fragments — but you hate how heavy it is — it’s often around 25 pounds for the armor and outer tactical vest (more if you add the plate inserts to stop up to 7.62 mm rounds).
It’s bulky — and you really can’t move as well in it. In fact, in one firefight, a medic removed his body armor to reach wounded allies, earning a Distinguished Service Cross.
Imagine if the body armor were just another part of your clothes, like a light jacket. Imagine not having to haul around those extra 30 pounds. Well, troops may not have to imagine much longer. According to a release from the Advanced Science Research Center at the City University of New York, body armor could soon have the thickness of just two atoms. This is due to how graphene acts under certain conditions.
Physicists Just Discovered The First Elusive Candidate For a 3D Quantum Spin Liquid
Physicists in the US have discovered a material that could qualify as the first known three-dimensional example of a quantum spin liquid — an exotic theoretical phase of matter.
Quantum spin liquids were first predicted by scientists back in the 1970s. While researchers have studied them for decades, these phases largely remain a theoretical concept, although that’s not the same as saying they don’t exist.
To confuse you further, quantum spin liquids aren’t actually liquids, but a kind of solid, magnetic matter that exhibits a strange form of behaviour at the subatomic particle level, specifically in terms of its electrons.
Could vacuum physics be revealed by laser-driven microbubbles?
A vacuum is generally thought to be nothing but empty space. But in fact, a vacuum is filled with virtual particle-antiparticle pairs of electrons and positrons that are continuously created and annihilated in unimaginably short time-scales.
The quest for a better understanding of vacuum physics will lead to the elucidation of fundamental questions in modern physics, which is integral in unraveling the mysteries of space, such as the Big Bang. However, the laser intensity required to forcibly separate the virtual pairs and cause them to appear not as virtual particles but real particles would be 10 million times higher than current laser technology is capable of. This field intensity is the so-called Schwinger limit, named a half-century ago after the American Nobel laureate Julian Schwinger.
In 2018, scientists at Osaka University discovered a novel mechanism that they called a microbubble implosion (MBI). In MBIs, super-high-energy hydrogen ions (relativistic protons) are emitted at the moment when bubbles shrink to atomic size through the irradiation of hydrides with micron-sized spherical bubbles by ultraintense, ultrashort laser pulses.
Bottomonium particles don’t go with the flow
A few millionths of a second after the Big Bang, the universe was so dense and hot that the quarks and gluons that make up protons, neutrons and other hadrons existed freely in what is known as the quark–gluon plasma. The ALICE experiment at the Large Hadron Collider (LHC) can recreate this plasma in high-energy collisions of beams of heavy ions of lead. However, ALICE, as well as any other collision experiments that can recreate the plasma, cannot observe this state of matter directly. The presence and properties of the plasma can only be deduced from the signatures it leaves on the particles that are produced in the collisions.
In a new article, presented at the ongoing European Physical Society conference on High-Energy Physics, the ALICE collaboration reports the first measurement of one such signature—the elliptic flow—for upsilon particles produced in lead–lead LHC collisions.
The upsilon is a bottomonium particle, consisting of a bottom (often also called beauty) quark and its antiquark. Bottomonia and their charm-quark counterparts, charmonium particles, are excellent probes of the quark–gluon plasma. They are created in the initial stages of a heavy-ion collision and therefore experience the entire evolution of the plasma, from the moment it is produced to the moment it cools down and gives way to a state in which hadrons can form.
Artificial intelligence designs metamaterials used in the invisibility cloak
Metamaterials are artificial materials engineered to have properties not found in naturally occurring materials, and they are best known as materials for invisibility cloaks often featured in sci-fi novels or games. By precisely designing artificial atoms smaller than the wavelength of light, and by controlling the polarization and spin of light, researchers achieve new optical properties that are not found in nature. However, the current process requires much trial and error to find the right material. Such efforts are time-consuming and inefficient; artificial intelligence (AI) could provide a solution for this problem.
The research group of Prof. Junsuk Rho, Sunae So and Jungho Mun of Department of Mechanical Engineering and Department of Chemical Engineering at POSTECH have developed a design with a higher degree of freedom that allows researchers to choose materials and design photonic structures arbitrarily by using deep learning. Their findings are published in several journals including Applied Materials and Interfaces, Nanophotonics, Microsystems & Nanoengineering, Optics Express, and Scientific Reports.
AI can be trained with a vast amount of data, and it can learn designs of various metamaterials and the correlation between photonic structures and their optical properties. Using this training process, it can provide a design method that makes a photonic structure with desired optical properties. Once trained, it can provide a desired design promptly and efficiently. This has already been researched at various institutions in the U.S. such as MIT, Stanford University and Georgia Institute of Technology. However, the previous studies require inputs of materials and structural parameters beforehand, and adjusting photonic structures afterwards.
Cosmic Ray Particle Scans Reveal Details of a Mysterious Underground Vault in Russia
Hidden underneath the Naryn-Kala fortress in Derbent, Russia, is a mysterious subterranean vault — a buried structure whose original purpose has been unknown for decades. Now, thanks to clever use of scanning technology, we might finally know what the building is.
Have fusion, will travel
The idea of propelling rockets and spaceships using the power of the atom is nothing new: the Manhattan Project in the mid-1940s as well as countless endeavours by NASA in the following decades all explored the possibility of using fission-based reactions to provide lift-off thrust. Today, progress made in controlled nuclear fusion has opened a new world of possibilities.
Path to Million Qubit Quantum Computers Using Atoms and Lasers
Atom Computing is building quantum computers using individually controlled atoms.
Ben has shown that neutral atoms could be more scalable, and could build a stable solution to create and maintain controlled quantum states. He used his expertise to lead efforts at Intel on their 10nm semiconductor chip, and then to lead research and development of the first cloud-accessible quantum computer at Rigetti.
Physicists Reverse Time for Tiny Particles Inside a Quantum Computer
Time goes in one direction: forward. Little boys become old men but not vice versa; teacups shatter but never spontaneously reassemble. This cruel and immutable property of the universe, called the “arrow of time,” is fundamentally a consequence of the second law of thermodynamics, which dictates that systems will always tend to become more disordered over time. But recently, researchers from the U.S. and Russia have bent that arrow just a bit — at least for subatomic particles.
In the new study, published Tuesday (Mar. 12) in the journal Scientific Reports, researchers manipulated the arrow of time using a very tiny quantum computer made of two quantum particles, known as qubits, that performed calculations. [Twisted Physics: 7 Mind-Blowing Findings]
At the subatomic scale, where the odd rules of quantum mechanics hold sway, physicists describe the state of systems through a mathematical construct called a wave function. This function is an expression of all the possible states the system could be in — even, in the case of a particle, all the possible locations it could be in — and the probability of the system being in any of those states at any given time. Generally, as time passes, wave functions spread out; a particle’s possible location can be farther away if you wait an hour than if you wait 5 minutes.