Quantum effects prevent trapped atoms from thermalizing, despite being repeatedly jiggled through laser excitation.
Category: particle physics – Page 7
Swarm reveals growing weak spot in Earth’s magnetic field
Using 11 years of magnetic field measurements from the European Space Agency’s Swarm satellite constellation, scientists have discovered that the weak region in Earth’s magnetic field over the South Atlantic—known as the South Atlantic Anomaly—has expanded by an area nearly half the size of continental Europe since 2014.
Earth’s magnetic field is vital to life on our planet. It is a complex and dynamic force that protects us from cosmic radiation and charged particles from the sun.
It is largely generated by a global ocean of molten, swirling liquid iron that makes up the outer core around 3,000 km beneath our feet. Acting like a spinning conductor in a bicycle dynamo, it creates electrical currents, which in turn, generate our continuously changing electromagnetic field —but in reality the processes that generate the field are far more complex.
The playbook for perfect polaritons: Rules for creating quasiparticles that can power optical computers, quantum devices
Light is fast, but travels in long wavelengths and interacts weakly with itself. The particles that make up matter are tiny and interact strongly with each other, but move slowly. Together, the two can combine into a hybrid quasiparticle called a polariton that is part light, part matter.
In a new paper published today in Chem, a team of Columbia chemists has identified how to combine matter and light to get the best of both worlds: polaritons with strong interactions and fast, wavelike flow. These distinctive behaviors can be used to power optical computers and other light-based quantum devices.
“We’ve written a playbook for the ‘perfect’ polariton that will guide our research, and we hope, that of the entire field working on strong light-matter interactions,” said Milan Delor, associate professor of chemistry at Columbia.
Controlling atomic interactions in ultracold gas ‘at the push of a button’
Changing interactions between the smallest particles at the touch of a button: Quantum researchers at RPTU have developed a new tool that makes this possible. The new approach—a temporally oscillating magnetic field—has the potential to significantly expand fundamental knowledge in the field of quantum physics. It also opens completely new perspectives on the development of new materials.
Computer chips, imaging techniques such as magnetic resonance imaging, laser printers, transistors, and navigation systems: many milestones in our modern everyday world would not have been possible without the discoveries of quantum physics. What is remarkable is that it was only about a hundred years ago that physicists discovered that the world at the smallest scales cannot be explained by the laws of classical physics.
Atoms and their components, protons, neutrons, and electrons—but also light particles—sometimes exhibit physical behaviors that are unknown in the macroscopic world. To this day, the quantum world therefore holds unclear and surprising phenomena that—once understood and controllable—could revolutionize future technologies.
A new method to build more energy-efficient memory devices could lead to a sustainable data future
A research team led by Kyushu University has developed a new fabrication method for energy-efficient magnetic random-access memory (MRAM) using a new material called thulium iron garnet (TmIG) that has been attracting global attention for its ability to enable high-speed, low-power information rewriting at room temperature. The team hopes their findings will lead to significant improvements in the speed and power efficiency of high-computing hardware, such as that used to power generative AI.
The work is published in npj Spintronics.
The rapid spread of generative AI has made the power demand from data centers a global issue, creating an urgent need to improve the energy efficiency of the hardware that runs the technology.
USC engineers just made light smarter with “optical thermodynamics”
USC engineers have developed an optical system that routes light autonomously using thermodynamic principles. Rather than relying on switches, light organizes itself much like particles in a gas reaching equilibrium. The discovery could simplify and speed up optical communications and computing. It reimagines chaotic optical behavior as a tool for design rather than a limitation.
Magnetic ‘switchback’ detected near Earth for the first time
In recent years, NASA’s Parker Solar Probe has given us a close-up look at the sun. Among the probe’s revelations was the presence of numerous kinks, or “switchbacks,” in magnetic field lines in the sun’s outer atmosphere. These switchbacks are thought to form when solar magnetic field lines that point in opposite directions break and then snap together, or “reconnect,” in a new arrangement, leaving telltale zigzag kinks in the reconfigured lines.
In their article published in the Journal of Geophysical Research: Space Physics, E. O. McDougall and M. R. Argall now report observations of a switchback-shaped structure in Earth’s magnetic field, suggesting that switchbacks can also form near planets.
The researchers discovered the switchback while analyzing data from NASA’s Magnetospheric Multiscale mission, which uses four Earth-orbiting satellites to study Earth’s magnetic field. They detected a twisting disturbance in the outer part of Earth’s magnetosphere—the bubble of space surrounding our planet where a cocktail of charged particles known as plasma is pushed and pulled along Earth’s magnetic field lines.
A new scalable approach to realize a quantum communication network based on ytterbium-171 atoms
Quantum networks, systems consisting of connected quantum computers, quantum sensors or other quantum devices, hold the potential of enabling faster and safer communications. The establishment of these networks relies on a quantum phenomenon known as entanglement, which entails a link between particles or systems, with the quantum state of one influencing the other even when they are far apart.
The atom-based qubits used to establish quantum networks so far operate at visible or ultraviolet wavelength, which is not ideal for the transmission of signals over long distances via optical fibers. Converting these signals to telecom-band wavelengths, however, can reduce the efficiency of communication and introduce undesirable signals that can disrupt the link between qubits.
A research team at University of Illinois at Urbana-Champaign, led by Prof. Jacob P. Covey recently realized telecom-band wavelength quantum networking using an array of ytterbium-171 atoms. Their paper, published in Nature Physics, introduces a promising approach to realize high-fidelity entanglement between atoms and optical photons generated directly in the telecommunication band.
Researchers transmit photons from moving plane in major quantum leap
A consortium of German researchers has successfully transmitted individual photons from a moving aircraft, captured them in a mobile ground station, and verified their quantum states.
The experiment, a key part of Germany’s QuNET initiative, marks a critical step towards building a global, tap-proof quantum communication network.
The research team successfully measured various quantum channels between the aircraft and the ground, sent the light particles to a sophisticated ion trap, and tested technologies vital for quantum key distribution (QKD).
Strain engineering enhances spin readout in quantum technologies, study shows
Quantum defects are tiny imperfections in solid crystal lattices that can trap individual electrons and their “spin” (i.e., the internal angular momentum of particles). These defects are central to the functioning of various quantum technologies, including quantum sensors, computers and communication systems.
Reliably predicting and controlling the behavior of quantum defects is thus very important, as it could pave the way for the development of better performing quantum systems tailored for specific applications. A property closely linked to the dependability of quantum technologies is the so-called spin readout contrast, which essentially determines how clear it is to distinguish between two different spin states in a system.
Researchers at the Harbin Institute of Technology (Shenzhen), the HUN-REN Wigner Research Center for Physics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences and other institutes recently showed that strain engineering (i.e., stretching or compressing materials) could be used to control how quantum defects behave and enhance spin readout contrast in quantum systems.