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Category: particle physics – Page 308

Physicists confirm existence of “demon” particle

A “demon” particle that has been haunting physicists for nearly 70 years has been found in an experiment by American researchers.

It is not a particle in the traditional sense like a proton or electron. It is a “composite” particle made up of a combination of electrons, in a solid.

In 1956, theoretical physicist David Pines predicted that electrons in a solid could do something strange. Electrons have both mass and charge. But Pines asserted that combinations of electrons in a solid could form a composite particle that is massless, has no charge and does not interact with light.

A new ‘spin’ on ergodicity breaking

In a recent Science paper, researchers led by JILA and NIST Fellow Jun Ye, along with collaborators JILA and NIST Fellow David Nesbitt, scientists from the University of Nevada, Reno, and Harvard University, observed novel ergodicity-breaking in C60, a highly symmetric molecule composed of 60 carbon atoms arranged on the vertices of a “soccer ball” pattern (with 20 hexagon faces and 12 pentagon faces).

Their results revealed ergodicity breaking in the rotations of C60. Remarkably, they found that this ergodicity breaking occurs without symmetry breaking and can even turn on and off as the molecule spins faster and faster. Understanding ergodicity breaking can help scientists design better-optimized materials for energy and heat transfer.

Many everyday systems exhibit “ergodicity” such as heat spreading across a frying pan and smoke filling a room. In other words, matter or energy spreads evenly over time to all system parts as energy conservation allows. On the other hand, understanding how systems can violate (or “break”) ergodicity, such as magnets or superconductors, helps scientists understand and engineer other exotic states of matter.

Research team simulates super diffusion on a quantum computer

Trinity’s quantum physicists in collaboration with IBM Dublin have successfully simulated super diffusion in a system of interacting quantum particles on a quantum computer.

This is the first step in doing highly challenging quantum transport calculations on quantum hardware and, as the hardware improves over time, such work promises to shed new light in condensed matter physics and materials science.

The work is one of the first outputs of the TCD-IBM predoctoral scholarship programwhich was recently established where IBM hires Ph.D. students as employees while being co-supervised at Trinity. The paper was published recently in npj Quantum Information.

Study discovers pairing of electrons in artificial atoms, a quantum state predicted more than 50 years ago

Researchers from the Department of Physics at Universität Hamburg, observed a quantum state that was theoretically predicted more than 50 years ago by Japanese theoreticians but so far eluded detection. By tailoring an artificial atom on the surface of a superconductor, the researchers succeeded in pairing the electrons of the so-called quantum dot, thereby inducing the smallest possible version of a superconductor. The work appears in the journal Nature.

Usually, electrons repel each other due to their negative charge. This phenomenon has a huge impact on many materials properties such as the electrical resistance. The situation changes drastically if the electrons are “glued” together to pairs thereby becoming bosons. Bosonic pairs do not avoid each other like single electrons, but many of them can reside at the very same location or do the very same motion.

One of the most intriguing properties of a material with such electron pairs is superconductivity, the possibility to let an electrical current flow through the material without any . For many years, superconductivity has found many important technological applications, including imaging or highly sensitive detectors for magnetic fields.

IonQ Says Reaching #AQ 64 will be a ChatGPT Moment for Quantum Computing

Not many pure-play quantum computing start-ups have dared to go public. So far, the financial markets have tended to treat the newcomers unsparingly. One exception is IonQ, who along with D-Wave and Rigetti, reported quarterly earnings last week. Buoyed by hitting key technical and financial goals, IonQ’s stock is up ~400% (year-to-date) and CEO Peter Chapman is taking an aggressive stance in the frothy quantum computing landscape where error correction – not qubit count – has increasingly taken center stage as the key challenge.

This is all occurring at a time when a wide variety of different qubit types are vying for dominance. IBM, Google, and Rigetti are betting on superconducting-based qubits. IonQ and Quantinuuum use trapped ions. Atom Computing and QuEra use neutral atoms. PsiQuantum and Xanadu rely on photonics-based qubits. Microsoft is exploring topological qubits based on the rare Marjorana particle. And more are in the works.

It’s not that the race to scale up qubit-count has ended. IBM has a 433-plus qubit device (Osprey) now and is scheduled to introduce 1100-qubit device (Condor) late this year. Several other quantum computer companies have devices in the 50–100 qubit range. IonQ’s latest QPU, Forte, has 32 qubits. The challenge they all face is that current error rates remain so high that it’s impractical to reliably run most applications on the current crop of QPUs.

Switching ‘spin’ on and off (and up and down) in quantum materials at room temperature

Researchers have found a way to control the interaction of light and quantum ‘spin’ in organic semiconductors, that works even at room temperature.

Spin is the term for the intrinsic angular momentum of electrons, which is referred to as up or down. Using the up/down spin states of electrons instead of the 0 and 1 in conventional computer logic could transform the way in which computers process information. And sensors based on quantum principles could vastly improve our abilities to measure and study the world around us.

An international team of researchers, led by the University of Cambridge, has found a way to use particles of light as a ‘switch’ that can connect and control the spin of electrons, making them behave like tiny magnets that could be used for quantum applications.

This is the most accurate image of an atom

A mysterious quantum phenomenon reveals an image of an atom like never before. You can even see the difference between protons and neutrons.

The Relativistic Heavy Ion Accelerator (RHIC), from the Brookhaven Laboratory in the United States, is a sophisticated device capable of accelerating gold ions to a speed of up to 99.995% that of light. Thanks to him, it has recently been possible to verify, for example, Einstein’s famous equation E=mc2.

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