Mirrors can now hide particles from quantum noise—flipping conventional physics on its head.
Category: particle physics – Page 16
Quantum computing and photonics discovery potentially shrinks critical parts by 1,000 times
Researchers have made a discovery that could make quantum computing more compact, potentially shrinking essential components 1,000 times while also requiring less equipment. The research is published in Nature Photonics.
A class of quantum computers being developed now relies on light particles, or photons, created in pairs linked or “entangled” in quantum physics parlance. One way to produce these photons is to shine a laser on millimeter-thick crystals and use optical equipment to ensure the photons become linked. A drawback to this approach is that it is too big to integrate into a computer chip.
Now, Nanyang Technological University, Singapore (NTU Singapore) scientists have found a way to address this approach’s problem by producing linked pairs of photons using much thinner materials that are just 1.2 micrometers thick, or about 80 times thinner than a strand of hair. And they did so without needing additional optical gear to maintain the link between the photon pairs, making the overall set-up simpler.
Laser Cooling is Optimized for Efficiency
A new laser-based cooling scheme approaches the maximum efficiency that is theoretically achievable.
Much of the progress in 20th-century physics has centered around understanding the interaction between light and matter. The availability of well-controlled light sources—lasers—enabled experimental exploration of controlled light–matter interactions and, specifically, methods to cool atoms close to absolute zero temperatures [1, 2]. Several laser-cooling methods, such as Doppler cooling and resolved sideband cooling, are used routinely to prepare controlled quantum states of atoms. Brennen de Neeve of the Swiss Federal Institute of Technology (ETH) Zurich and his colleagues now show just how efficient a laser-cooling process can be [3] (Fig. 1). They demonstrate a laser-cooling method that uses a “spin-dependent force” to transfer motional entropy from the atom into the entropy of its internal degrees of freedom.
‘Intercrystals’ pave the way for greener electronics and quantum technologies
Rutgers University–New Brunswick researchers have discovered a new class of materials—called intercrystals—with unique electronic properties that could power future technologies.
Intercrystals exhibit newly discovered forms of electronic properties that could pave the way for advancements in more efficient electronic components, quantum computing and environmentally friendly materials, the scientists said.
As described in a report in the science journal Nature Materials, the scientists stacked two ultrathin layers of graphene, each a one-atom-thick sheet of carbon atoms arranged in a hexagonal grid. They twisted them slightly atop a layer of hexagonal boron nitride, a hexagonal crystal made of boron and nitrogen. A subtle misalignment between the layers that formed moiré patterns—patterns similar to those seen when two fine mesh screens are overlaid—significantly altered how electrons moved through the material, they found.
Faster, more stable plasma simulations help advance chip manufacturing
Plasma—the electrically charged fourth state of matter—is at the heart of many important industrial processes, including those used to make computer chips and coat materials.
Simulating those plasmas can be challenging, however, because millions of math operations must be performed for thousands of points in the simulation, many times per second. Even with the world’s fastest supercomputers, scientists have struggled to create a kinetic simulation—which considers individual particles—that is detailed and fast enough to help them improve those manufacturing processes.
Now, a new method offers improved stability and efficiency for kinetic simulations of what’s known as inductively coupled plasmas. The method was implemented in a code developed as part of a private-public partnership between the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) and chip equipment maker Applied Materials Inc., which is already using the tool. Researchers from the University of Alberta, PPPL and Los Alamos National Laboratory contributed to the project.
Record-high Curie temperature achieved in ferromagnetic semiconductor
Ferromagnetic semiconductors (FMSs) combine the unique properties of semiconductors and magnetism, making them ideal candidates for developing spintronic devices that integrate both semiconductor and magnetic functionalities. However, one of the key challenges in FMSs has been achieving high Curie temperatures (TC) that enable their stable operation at room temperature.
Though previous studies achieved a TC of 420 K, which is higher than room temperature, it was insufficient for effectively operating the spin functional materials, highlighting the demand for an increase in TC among FMSs. This challenge has been featured among the 125 unsolved questions selected by the journal Science in 2005.
Materials such as (Ga, Mn)As exhibit low TC, limiting their practical use in spintronic devices. While adding Fe to narrow bandgap semiconductors like GaSb seemed promising, incorporating high concentrations of Fe while maintaining crystallinity proved difficult, restricting the attainable TC.
Cosmic-ray-induced correlated errors in superconducting qubit array
The correlated errors in superconducting qubits have been linked to high-energy particle impacts from cosmic rays, but a direct observation has been lacking. Here, the authors measure the quasiparticle bursts and correlated errors and separate the contributions of cosmic-ray muons and γ-rays in a 63-qubit processor.
Overlooked electron property opens up new avenues for orbitronics
The orbital angular momentum of electrons has long been considered a minor physical phenomenon, suppressed in most crystals and largely overlooked. Scientists at Forschungszentrum Jülich have now discovered that in certain materials it is not only preserved but can even be actively controlled. This is due to a property of the crystal structure called chirality, which also influences many other processes in nature.
The discovery has the potential to lead to a new class of electronic components capable of transmitting information with exceptional robustness and energy efficiency.
From electronics to spintronics, and now to orbitronics: In classical electronics, it is primarily the charge of the electron that counts. In modern approaches such as quantum computing and spintronics, the focus has shifted to the electron’s spin.
Researchers Used a One-Atom Quantum Computer to Simulate Real Molecules Over Time
We also simulated “open-system” dynamics, where the molecule interacts with its environment. This is typically a much harder problem for classical computers.
By injecting controlled noise into the ion’s environment, we replicated how real molecules lose energy. This showed environmental complexity can also be captured by quantum simulation.