Researchers from Lancaster University and Radboud University Nijmegen have managed to generate propagating spin waves at the nanoscale and discovered a novel pathway to modulate and amplify them.
Category: quantum physics – Page 248
New device precisely controls photon emission for more efficient portable screens
Recently, a team of chemists, mathematicians, physicists and nano-engineers at the University of Twente in the Netherlands developed a device to control the emission of photons with unprecedented precision. This technology could lead to more efficient miniature light sources, sensitive sensors, and stable quantum bits for quantum computing.
Fewer mini black holes existed in early universe, finds study
Fewer miniature black holes found:
Researchers at the University of Tokyo have found that the universe contains far fewer miniature black holes than previously thought, potentially shaking up current theories about dark matter.
Using advanced quantum field theory, typically reserved for subatomic particles, they applied this understanding to the early universe. They discovered new insights into primordial black holes (PBHs), which have been a strong contender for dark matter. Upcoming observations could soon confirm their surprising findings.
The thinnest lens on Earth is only three atoms thick
Lenses are used to bend and focus light. Normal lenses rely on their curved shape to achieve this effect, but physicists from the University of Amsterdam and Stanford University have made a flat lens of only three atoms thick which relies on quantum effects. This type of lens could be used in future augmented reality glasses.
The findings have been published in Nano Letters (“Temperature-Dependent Excitonic Light Manipulation with Atomically Thin Optical Elements”).
The thinnest lens on Earth, made of concentric rings of tungsten disulphide (WS2), uses excitons to efficiently focus light. The lens is as thick as a single layer of WS2, just three atoms thick. The bottom left shows an exciton: an excited electron bound to the positively charged ‘hole’ in the atomic lattice. (Image: Ludovica Guarneri and Thomas Bauer)
Exploring Uncharted Territory: Physicists Unveil Infinite Possibilities of Quantum States
A new method developed by Amsterdam researchers uses non-Gaussian states to efficiently describe and configure quantum spin-boson systems, promising advancements in quantum computing and sensing.
Many modern quantum devices operate using groups of qubits, or spins, which have just two energy states: ‘0’ and ‘1’. However, in actual devices, these spins also interact with photons and phonons, collectively known as bosons, making the calculations much more complex. In a recent study published in Physical Review Letters, researchers from Amsterdam have developed a method to effectively describe these spin-boson systems. This breakthrough could help in efficiently setting up quantum devices to achieve specific desired states.
Quantum devices use the quirky behavior of quantum particles to perform tasks that go beyond what ‘classical’ machines can do, including quantum computing, simulation, sensing, communication, and metrology. These devices can take many forms, such as a collection of superconducting circuits, or a lattice of atoms or ions held in place by lasers or electric fields.
Quantum time travel: The experiment to ‘send a particle into the past’
Time loops have long been the stuff of science fiction. Now, using the rules of quantum mechanics, we have a way to effectively transport a particle back in time – here’s how.
Let there be matter: Simulating the creation of matter from photon–photon collisions
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A team led by researchers at Osaka University and University of California, San Diego has conducted simulations of creating matter solely from collisions of light particles. Their method circumvents what would otherwise be the intensity limitations of modern lasers and can be readily implemented by using presently available technology. This work might help experimentally test long-standing theories such as the Standard Model of particle physics, and possibly the need to revise them.
One of the most striking predictions of quantum physics is that matter can be generated solely from light (i.e., photons), and in fact, the astronomical bodies known as pulsars achieve this feat. Directly generating matter in this manner has not been achieved in a laboratory, but it would enable further testing of the theories of basic quantum physics and the fundamental composition of the universe.
In a study published in Physical Review Letters, a team led by researchers at Osaka University has simulated conditions that enable photon –photon collisions, solely by using lasers. The simplicity of the setup and ease of implementation at presently available laser intensities make it a promising candidate for near-future experimental implementation.
Research team demonstrates modular, scalable hardware architecture for a quantum computer
The team spent years perfecting an intricate process for manufacturing two-dimensional arrays of atom-sized qubit microchiplets and transferring thousands of them onto a carefully prepared complementary metal-oxide semiconductor (CMOS) chip. This transfer can be performed in a single step.
“We will need a large number of qubits, and great control over them, to really leverage the power of a quantum system and make it useful. We are proposing a brand new architecture and a fabrication technology that can support the scalability requirements of a hardware system for a quantum computer,” says Linsen Li, an electrical engineering and computer science (EECS) graduate student and lead author of a paper on this architecture.
Physicists Demonstrate Room Temp Quantum Storage in 2D Material
Microscopic chinks in material just several atoms thick have the potential to advance a multitude of quantum technologies, new research shows – getting us closer to the widespread use of quantum networks and sensors.
Right now, storing quantum data in the spin properties of electrons, known as spin coherence, requires a very particular and delicate laboratory setup. It’s not something you can do without a carefully controlled environment.
Here, an international team of researchers managed to demonstrate observable spin coherence at room temperature, using the tiny defects in a layered 2D material called Hexagonal Boron Nitride (hBN).
Speeding up calculations that reveal how electrons interact in materials
Materials scientists and engineers would like to know precisely how electrons interact and move in new materials and how the devices made with them will behave. Will the electrical current flow easily within the material? Is there a temperature at which the material will become superconducting, enabling current to flow without a power source? How long will the quantum state of an electron spin be preserved in new electronic and quantum devices?