Lifeboat Foundation

A new method to measure the arrival times of electrons could aid in the design of future electron microscopes.

For researchers working to develop the next generation of electron microscopes, understanding the details of electron beams is essential. Now a research team has observed the weak repulsion of electrons in a continuous beam with the highest precision to date by measuring the number of electrons arriving at a detector within a timeframe of less than 1 picosecond (ps) [1]. With improvements, the new technique may be able to pick up the repulsion attributable to the Pauli exclusion principle. The researchers think the work may eventually help engineers design more sensitive electron microscopes based on quantum principles.

Many natural events such as rain falling are uncorrelated: the fall of each raindrop is independent of every other raindrop. Given a certain time window, say 1 second, the likelihood that zero, one, two, or more raindrops will fall within a certain area is predicted by a statistical distribution called a Poissonian. If, however, the raindrops could interact, then their arrivals might be correlated or anticorrelated—the drops could fall together more often or less often, depending on whether the interaction is attractive or repulsive. Then the probability of similarly timed raindrops would be either super-Poissonian (occurring more often) or sub-Poissonian (occurring less often).

A protein-based motor uses a trimming mechanism to move forward across a field of grass-like peptide segments.

The clumpy structure of a ring of gas ejected by the progenitor star of the supernova 1987A could have formed when vortices in the gas interacted.

Researchers at the National University of Singapore (NUS) have developed an innovative method for creating carbon-based quantum materials atom by atom. This method combines the use of scanning probe microscopy with advanced deep neural networks. The achievement underlines the capabilities of artificial intelligence (AI) in manipulating materials at the sub-angstrom level, offering significant advantages for basic science and potential future uses.

Open-shell magnetic nanographenes represent a technologically appealing class of new carbon-based quantum materials, which host robust π-spin centers and non-trivial collective quantum magnetism. These properties are crucial for developing high-speed electronic devices at the molecular level and creating quantum bits, the building blocks of quantum computers.

Continue reading “Quantum Leap in Material Science: Researchers Unveil AI-Powered Atomic Fabrication Technique” »

Physicists are pushing the limits of atomic clock accuracy by using spin-squeezed states, achieving groundbreaking control over quantum noise and entanglement, leading to potential leaps in quantum metrology.

While atomic clocks are already the most precise timekeeping devices in the universe, physicists are working hard to improve their accuracy even further. One way is by leveraging spin-squeezed states in clock atoms. Spin-squeezed states are entangled states in which particles in the system conspire to cancel their intrinsic quantum noise. These states, therefore, offer great opportunities for quantum-enhanced metrology since they allow for more precise measurements. Yet, spin-squeezed states in the desired optical transitions with little outside noise have been hard to prepare and maintain.

One particular way to generate a spin-squeezed state, or squeezing, is by placing the clock atoms into an optical cavity, a set of mirrors where light can bounce back and forth many times. In the cavity, atoms can synchronize their photon emissions and emit a burst of light far brighter than from any one atom alone, a phenomenon referred to as superradiance. Depending on how superradiance is used, it can lead to entanglement, or alternatively, it can instead disrupt the desired quantum state.

An MIT team precisely controlled an ultrathin magnet at room temperature, which could enable faster, more efficient processors and computer memories.

Experimental computer memories and processors built from magnetic materials use far less energy than traditional silicon-based devices. Two-dimensional magnetic materials, composed of layers that are only a few atoms thick, have incredible properties that could allow magnetic-based devices to achieve unprecedented speed, efficiency, and scalability.

While many hurdles must be overcome until these so-called van der Waals magnetic materials can be integrated into functioning computers, MIT researchers took an important step in this direction by demonstrating precise control of a van der Waals magnet at room temperature.

An international team used the James Webb Space Telescope to study a protoplanetary disc in the Orion Nebula, revealing how massive stars significantly influence the formation of planetary systems. They discovered that intense ultraviolet radiation from these stars can prevent the formation of Jupiter-like planets in systems like d203-506, providing new insights into the complexities of how planetary systems develop.

How do planetary systems such as the Solar System form? To find out, CNRS scientists taking part in an international research team^[1] studied a stellar nursery, the Orion Nebula, using the James Webb Space Telescope.^[2] By observing a protoplanetary disc named d203-506, they have discovered the key role played by massive stars in the formation of such nascent planetary systems.^[3].

Mid-infrared and terahertz laser pulses serve as potent instruments for altering the characteristics of quantum materials by specifically tailoring their crystal lattice. The induction of ferroelectricity in SrTiO₃ when exposed to mid-infrared light is a significant example of this phenomenon. In this process, SrTiO₃ undergoes a change to a state where electrical dipoles are permanently aligned, a condition not found in its natural state of equilibrium. The process driving this remarkable transformation remains a mystery.

Now, a team of researchers of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) in Germany and the SLAC National Accelerator Laboratory in the United States has performed an experiment at the SwissFEL X-ray Free-Electron Laser to identify the intrinsic interactions relevant to creating this state. The new insight was gained not by detecting the position of the atoms, but by measuring the fluctuations of these atomic positions.

The result provides evidence that these fluctuations are reduced, which may explain why the dipolar structure is more ordered than in equilibrium, and why a ferroelectric state could be induced. The work by the Cavalleri group has appeared in Nature Materials.

Researchers analyzed emission data from quasar 3C 273 using two theoretical models, revealing complexities in understanding quasar behavior and the mechanics of supermassive black holes.

In a new paper in The Astrophysical Journal, JILA Fellow Jason Dexter, graduate student Kirk Long, and other collaborators compared two main theoretical models for emission data for a specific quasar, 3C 273. Using these theoretical models, astrophysicists like Dexter can better understand how these quasars form and change over time.

Quasars, or active galactic nuclei (AGN), are believed to be powered by supermassive black holes at their centers. Among the brightest objects in the universe, quasars emit a brilliant array of light across the electromagnetic spectrum. This emission carries vital information about the nature of the black hole and surrounding regions, providing clues that astrophysicists can exploit to better understand the black hole’s dynamics.