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Controlling electron interference in time with chirped laser pulses

In quantum mechanics, particles such as electrons act like waves and can even interfere with themselves—a striking and counterintuitive feature that defies our classical view of reality. We know this kind of interference happens in space, where different paths can overlap and combine, but what if we could take it further? What if we could control quantum interference in time, where electrons created at different moments interfere?

In a new study published in Physical Review Letters, a team of researchers developed a novel technique—chirped laser-assisted dynamic interference—to manipulate temporal during photoionization.

By using extreme-ultraviolet pulses with time-varying central frequency, in combination with intense infrared laser fields, they guided electron motion with unprecedented precision.

The Solar Wind Is Hiding Strange Particles That Could Rewrite Space Weather

Data may challenge and reshape current models of solar wind evolution.

A recent study led by Dr. Michael Starkey of the Southwest Research Institute has delivered the first observational evidence from the Magnetospheric Multiscale (MMS) Mission of pickup ions (PUIs) and their related wave activity in the solar wind near Earth. NASA launched the MMS mission in 2015, deploying four spacecraft to study Earth’s magnetosphere, the magnetic field that protects the planet from harmful solar and cosmic radiation.

Formation and behavior of PUIs.

Measuring the quantum W state

Kyoto, Japan — The concept of quantum entanglement is emblematic of the gap between classical and quantum physics. Referring to a situation in which it is impossible to describe the physics of each photon separately, this key characteristic of quantum mechanics defies the classical expectation that each particle should have a reality of its own, which gravely concerned Einstein. Understanding the potential of this concept is essential for the realization of powerful new quantum technologies.

Primordial black hole’s final burst may solve neutrino mystery

The last gasp of a primordial black hole may be the source of the highest-energy “ghost particle” detected to date, a new MIT study proposes.

In a paper appearing today in Physical Review Letters, MIT physicists put forth a strong theoretical case that a recently observed, highly energetic neutrino may have been the product of a primordial black hole exploding outside our solar system.

Neutrinos are sometimes referred to as ghost particles, for their invisible yet pervasive nature: They are the most abundant particle type in the universe, yet they leave barely a trace. Scientists recently identified signs of a neutrino with the highest energy ever recorded, but the source of such an unusually powerful particle has yet to be confirmed.

Novel catalyst design could make green hydrogen production more efficient and durable

A new type of catalyst—a material that speeds up chemical reactions—that could make the production of clean hydrogen fuel more efficient and long-lasting has been developed by a team led by City University of Hong Kong, including researchers from Hong Kong, mainland China, and Japan.

This breakthrough uses high-density single atoms of iridium (a rare metal) to greatly improve the process of splitting water into and , which is key to like hydrogen fuel cells and large-scale energy storage.

The researchers created a highly stable and active by placing single iridium atoms on ultra-thin sheets made of cobalt and cerium compounds. Called CoCe–O–IrSA, the final product performs exceptionally well in the water-splitting process. It requires very little extra energy (just 187 mV of overpotential at 100 mA cm-2) to drive the oxygen evolution reaction at a high rate, and it stays stable for more than 1,000 hours under demanding conditions.

MicroBooNE detector excludes electron neutrino cause of MiniBooNE anomaly

A recent Physical Review Letters publication presents a thorough analysis of MicroBooNE detector data, investigating the anomalous surplus of neutrino-like events detected by the preceding MiniBooNE experiment.

In 1990, the LSND (Liquid Scintillator Neutrino Detector) experiment observed an anomalous signal indicating the potential existence of sterile neutrinos—a fourth neutrino species beyond the three established flavors (electron, muon, and tau neutrinos).

MiniBooNE was constructed to examine this anomaly utilizing the same neutrino beam methodology. However, instead of resolving the mystery, MiniBooNE discovered an anomaly of its own.

‘Like talking on the telephone’: Quantum computing engineers get atoms chatting long distance

UNSW engineers have made a significant advance in quantum computing: they created ‘quantum entangled states’—where two separate particles become so deeply linked they no longer behave independently—using the spins of two atomic nuclei. Such states of entanglement are the key resource that gives quantum computers their edge over conventional ones.

The research is published in the journal Science, and is an important step toward building large-scale quantum computers—one of the most exciting scientific and technological challenges of the 21st century.

Lead author Dr. Holly Stemp says the achievement unlocks the potential to build the future microchips needed for quantum computing using existing technology and manufacturing processes.

‘Quantum squeezing’ a nanoscale particle for the first time

Researchers Mitsuyoshi Kamba, Naoki Hara, and Kiyotaka Aikawa of the University of Tokyo have successfully demonstrated quantum squeezing of the motion of a nanoscale particle, a motion whose uncertainty is smaller than that of quantum mechanical fluctuations.

As enhancing the measurement precision of sensors is vital in many modern technologies, the achievement paves the way not only for basic research in fundamental physics but also for applications such as accurate autonomous driving and navigation without a GPS signal. The findings are published in the journal Science.

The physical world at the macroscale, from to planets, is governed by the laws of discovered by Newton in the 17th century. The physical world at the microscale, atoms and below, is governed by the laws of quantum mechanics, which lead to phenomena generally not observed at the macroscale.

Shape-shifting collisions offer new tool for studying early matter produced in Big Bang’s aftermath

This summer, the Large Hadron Collider (LHC) took a breath of fresh air. Normally filled with beams of protons, the 27-km ring was reconfigured to enable its first oxygen–oxygen and neon–neon collisions. First results from the new data, recorded over a period of six days by the ALICE, ATLAS, CMS and LHCb experiments, were presented during the Initial Stages conference held in Taipei, Taiwan, on 7–12 September.

Smashing into one another allows physicists to study the quark–gluon plasma (QGP), an extreme state of matter that mimics the conditions of the universe during its first microseconds, before atoms formed. Until now, exploration of this hot and dense state of free particles at the LHC relied on collisions between (like lead or xenon), which maximize the size of the plasma droplet created.

Collisions between lighter ions, such as oxygen, open a new window on the QGP to better understand its characteristics and evolution. Not only are they smaller than lead or xenon, allowing a better investigation of the minimum size of nuclei needed to create the QGP, but they are less regular in shape. A neon nucleus, for example, is predicted to be elongated like a bowling pin—a picture that has now been brought into sharper focus thanks to the new LHC results.

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