Physicists discuss experiments that could improve laboratory measurements of the super-light particle’s mass.
Category: particle physics – Page 123
Hydrogen (like many of us) acts weird under pressure. Theory predicts that when crushed by the weight of more than a million times our atmosphere, this light, abundant, normally gaseous element first becomes a metal, and even more strangely, a superconductor—a material that conducts electricity with no resistance.
Scientists have been eager to understand and eventually harness superconducting hydrogen-rich compounds, called hydrides, for practical applications—from levitating trains to particle detectors. But studying the behavior of these and other materials under enormous, sustained pressures is anything but practical, and accurately measuring those behaviors ranges somewhere between a nightmare and impossible.
Like the calculator did for arithmetic, and ChatGPT has done for writing five-paragraph essays, Harvard researchers think they have a foundational tool for the thorny problem of how to measure and image the behavior of hydride superconductors at high pressure.
Quantum materials have generated considerable interest for computing applications in the past several decades, but non-trivial quantum properties—like superconductivity or magnetic spin—remain in fragile states.
“When designing quantum materials, the game is always a fight against disorder,” said Robert Hovden, an associate professor of materials science and engineering at the University of Michigan.
Heat is the most common form of disorder that disrupts quantum properties. Quantum materials often only exhibit exotic phenomena at very low temperatures when the atom nearly stops vibrating, allowing the surrounding electrons to interact with one another and rearrange themselves in unexpected ways. This is why quantum computers are currently being developed in baths of liquid helium at −269 °C, or around −450 F. That’s just a few degrees above zero Kelvin (−273.15 °C).
Enhancing quantum features compensates for environmental losses, amplifying particle interactions, achieving entanglement at higher scales.
One of the oldest topics of contemporary science is where to draw the line between classical and quantum physics.
Abstract
The ability to engineer cavity-mediated interactions has emerged as a powerful tool for the generation of non-local correlations and the investigation of non-equilibrium phenomena in many-body systems. Levitated optomechanical systems have recently entered the multi-particle regime, with promise for using arrays of massive strongly coupled oscillators for exploring complex interacting systems and sensing. Here, by combining advances in multi-particle optical levitation and cavity-based quantum control, we demonstrate, for the first time, programmable cavity-mediated interactions between nanoparticles in a vacuum. The interaction is mediated by photons scattered by spatially separated particles in a cavity, resulting in strong coupling (Gzz/Ωz = 0.238 ± 0.005) that does not decay with distance within the cavity mode volume. We investigate the scaling of the interaction strength with cavity detuning and inter-particle separation and demonstrate the tunability of interactions between different mechanical modes. Our work paves the way towards exploring many-body effects in nanoparticle arrays with programmable cavity-mediated interactions, generating entanglement of motion, and using interacting particle arrays for optomechanical sensing.
A groundbreaking body of work led by Monash University physicists has opened a new pathway for understanding the universe’s fundamental physics.
The work, featured in an international review published in Progress in Particle and Nuclear Physics, follows nearly a decade of work by scientists at the School of Physics and Astronomy in the Faculty of Science at Monash University.
Gravitational waves have only recently been detected for the first time, offering an exciting opportunity to delve into the mysteries of particle physics through first-order phase transitions (FOPTs) in the early cosmos.
The question of where the boundary between classical and quantum physics lies is one of the longest-standing pursuits of modern scientific research, and in new research published today, scientists demonstrate a novel platform that could help us find an answer.
The laws of quantum physics govern the behavior of particles at miniscule scales, leading to phenomena such as quantum entanglement, where the properties of entangled particles become inextricably linked in ways that cannot be explained by classical physics.
Research in quantum physics helps us to fill gaps in our knowledge of physics and can give us a more complete picture of reality, but the tiny scales at which quantum systems operate can make them difficult to observe and study.
The entropy production rate is determined from the variances of the position and forces applied to a system of particles.
Gravitationally speaking, the universe is a noisy place. A hodgepodge of gravitational waves from unknown sources streams unpredictably around space, including possibly from the early universe.
Scientists have been looking for signs of these early cosmological gravitational waves, and a team of physicists have now shown that such waves should have a distinct signature due to the behavior of quarks and gluons as the universe cools. Such a finding would have a decisive impact on which models best describe the universe almost immediately after the Big Bang. The study is published in the journal Physical Review Letters.
Scientists first found direct evidence for gravitational waves in 2015 at the LIGO gravitational wave interferometers in the US. These are singular (albeit tiny amplitude) waves from a particular source, such as the merger of two black holes, which wash past Earth. Such waves cause the 4-km perpendicular arms of the interferometers to change length by miniscule (but different) amounts, the difference detected by changes in the resulting interference pattern as laser beams travel back and forth in the detector’s arms.
To study tiny “ghost particles” known as neutrinos, scientists with Fermilab’s DUNE project will beam them from Illinois to caverns in South Dakota.
