Toggle light / dark theme

MIT’s Electron Spin Magic Sparks Computing Evolution

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.

Physicists Unlock the Secrets of Light-Induced Ferroelectricity in Quantum Materials

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.

800-mile neutrino beam probes Earth in DUNE experiment

Scientists are eager to tackle perplexing questions using DUNE, such as the mystery of why the universe is made of matter and how black holes arise from exploding stars.

Moreover, they want to understand the potential connections between neutrinos, dark matter, and other yet-to-be-discovered particles.

These caverns will soon be home to four large neutrino detectors, each the size of a seven-story building.

Do black holes explode? The 50-year-old puzzle that challenges quantum physics

In hindsight, it seems prophetic that the title of a Nature paper published on 1 March 1974 ended with a question mark: “Black hole explosions?” Stephen Hawking’s landmark idea about what is now known as Hawking radiation1 has just turned 50. The more physicists have tried to test his theory over the past half-century, the more questions have been raised — with profound consequences for how we view the workings of reality.

In essence, what Hawking, who died six years ago today, found is that black holes should not be truly black, because they constantly radiate a tiny amount of heat. That conclusion came from basic principles of quantum physics, which imply that even empty space is a far-from-uneventful place. Instead, space is filled with roiling quantum fields in which pairs of ‘virtual’ particles incessantly pop out of nowhere and, under normal conditions, annihilate each other almost instantaneously.

However, at an event horizon, the spherical surface that defines the boundary of a black hole, something different happens. An event horizon represents a gravitational point of no return that can be crossed only inward, and Hawking realized that there two virtual particles can become separated. One of them falls into the black hole, while the other radiates away, carrying some of the energy with it. As a result, the black hole loses a tiny bit of mass and shrinks — and shines.

IceCube identifies seven astrophysical tau neutrino candidates

The IceCube Neutrino Observatory, a cubic-kilometer-sized neutrino telescope at the South Pole, has observed a new kind of astrophysical messenger. In a new study recently accepted for publication as an Editors’ Suggestion by the journal Physical Review Letters and available on the arXiv preprint server, the IceCube collaboration, including Penn State researchers, presented the discovery of seven of the once-elusive astrophysical tau neutrinos.

Quantum dance to the beat of a drum: Researchers observe how energy of single electron is tuned by surrounding atoms

Physicists at the University of Regensburg have choreographed the shift of a quantized electronic energy level with atomic oscillations faster than a trillionth of a second.

Throwing a ball into the air, one can transfer arbitrary energy to the ball such that it flies higher or lower. One of the oddities of quantum physics is that particles, e.g., electrons, can often only take on quantized energy values—as if the ball was leaping between specific heights, like steps of a ladder, rather than flying continuously.

Qubits and quantum computers as well as light-emitting quantum dots (Nobel Prize 2023) make use of this principle. However, electronic energy levels can be shifted by collisions with other electrons or atoms. Processes in the quantum world usually take place on atomic scales and are also incredibly fast.

Solid-State Qubits: Artificial Atoms Unlock Quantum Computing Breakthrough

JILA breakthrough in integrating artificial atoms with photonic circuits advances quantum computing efficiency and scalability.

In quantum information science, many particles can act as “bits,” from individual atoms to photons. At JILA, researchers utilize these bits as “qubits,” storing and processing quantum 1s or 0s through a unique system.

While many JILA Fellows focus on qubits found in nature, such as atoms and ions, JILA Associate Fellow and University of Colorado Boulder Assistant Professor of Physics Shuo Sun is taking a different approach by using “artificial atoms,” or semiconducting nanocrystals with unique electronic properties. By exploiting the atomic dynamics inside fabricated diamond crystals, physicists like Sun can produce a new type of qubit, known as a “solid-state qubit,” or an artificial atom.

/* */