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Archive for the ‘quantum physics’ category: Page 36

Jun 27, 2024

Is the ultimate nature of reality mental?

Posted by in categories: food, neuroscience, particle physics, quantum physics

Philosopher Wilfrid Sellars had a term for the world as it appears, the “manifest image.” This is the world as we perceive it. In it, an apple is an apple, something red or green with a certain shape, a range of sizes, a thing that we can eat, or throw.

The manifest image can be contrasted with the scientific image of the world. Where the manifest image has colors, the scientific one has electromagnetic radiation of certain wavelengths. Where the manifest image has solid objects, like apples, the scientific image has mostly empty space, with clusters of elementary particles, held together in configurations due to a small number of fundamental interactions.

The scientific image is often radically different from the manifest image, although how different it is depends on what level of organization is being examined. For many purposes, including scientific ones, the manifest image, which is itself a predictive theory of the world at a certain level or organization, works just fine. For example, an ethologist, someone who studies animal behavior, can generally do so without having to concern themselves about quantum fields and their interactions.

Jun 27, 2024

Physicists Uncover New Path to Quantum Computing: Infrared Illumination

Posted by in categories: computing, particle physics, quantum physics

Physicists at TU Graz have determined that certain molecules can be stimulated by pulses of infrared light to generate small magnetic fields. If experimental trials are also successful, this technique could potentially be applied in quantum computer circuits.

When molecules absorb infrared light, they start to vibrate as they receive energy. Andreas Hauser from the Institute of Experimental Physics at Graz University of Technology (TU Graz) used this well-understood process as a basis for exploring whether these vibrations could be harnessed to produce magnetic fields. Since atomic nuclei carry a positive charge, the movement of these charged particles results in the creation of a magnetic field.

Using the example of metal phthalocyanines – ring-shaped, planar dye molecules – Andreas Hauser and his team have now calculated that, due to their high symmetry, these molecules actually generate tiny magnetic fields in the nanometre range when infrared pulses act on them.

Jun 27, 2024

Mechanical Coupling to Spin Qubits

Posted by in categories: particle physics, quantum physics

While solid-state spin qubits show promise as quantum information platforms, their qubit-to-qubit interactions extend over too short a distance to connect many of them together, posing a problem for complex computations. Now Frankie Fung and colleagues from Harvard University have devised a mechanical method—involving a vibrating nanobeam—to connect distant spin qubits, potentially overcoming this issue [1].

A popular solid-state spin qubit is the nitrogen-vacancy (NV) center, a single-atom defect in a diamond crystal. This system is attractive for quantum information applications, as it has both a light-sensitive electron spin state (which offers a knob for controlling the qubit) and a long-lived nuclear spin state (which acts as memory). But direct interactions between NV centers are limited to a few nanometers.

To lengthen the connections, Fung and his colleagues propose using a nanobeam fitted with a micromagnet as an intermediary between distant NV centers. The idea is then to place a line of NV centers along the length of a scanning-probe-microscope tip and move the tip over the micromagnet. When a particular NV center comes close to the micromagnet, the magnetic-field interaction should entangle the vibrational state of the nanobeam with the spin state of that NV center. This quantum information is then shared with the next NV center along the line.

Jun 27, 2024

The surprising behavior of black holes in an expanding universe

Posted by in categories: cosmology, information science, quantum physics

A physicist investigating black holes has found that, in an expanding universe, Einstein’s equations require that the rate of the universe’s expansion at the event horizon of every black hole must be a constant, the same for all black holes. In turn this means that the only energy at the event horizon is dark energy, the so-called cosmological constant. The study is published on the arXiv preprint server.

“Otherwise,” said Nikodem Popławski, a Distinguished Lecturer at the University of New Haven, “the pressure of matter and curvature of spacetime would have to be infinite at a horizon, but that is unphysical.”

Black holes are a fascinating topic because they are about the simplest things in the universe: their only properties are mass, electric charge and angular momentum (spin). Yet their simplicity gives rise to a fantastical property—they have an event horizon at a critical distance from the black hole, a nonphysical surface around it, spherical in the simplest cases. Anything closer to the black hole, that is, inside the event horizon, can never escape the black hole.

Jun 27, 2024

Understanding quantum states: New research shows importance of precise topography in solid neon qubits

Posted by in categories: computing, quantum physics

Quantum computers have the potential to be revolutionary tools for their ability to perform calculations that would take classical computers many years to resolve.

But to make an effective quantum computer, you need a reliable quantum bit, or , that can exist in a simultaneous 0 or 1 state for a sufficiently long period, known as its coherence time.

One promising approach is trapping a on a solid surface, called an electron-on-solid-neon qubit. A study led by FAMU-FSU College of Engineering Professor Wei Guo that was published in Physical Review Letters shows new insight into the that describes the condition of electrons on such a qubit, information that can help engineers build this innovative technology.

Jun 27, 2024

Researchers capture detailed picture of electron acceleration in one shot

Posted by in categories: biotech/medical, quantum physics

Adjusting experimental methods achieved the first “single-shot” diagnosis of electron acceleration through a laser wakefield accelerator along a curved trajectory, according to a recent study led by University of Michigan researchers. The findings are published in the journal Physical Review Letters.

This optical-based technique could help engineers develop more powerful electron accelerators for fundamental studies of quantum and —or more compact accelerators for use in medicine and industry.

Compared to traditional accelerators which can be kilometers long, laser wakefield accelerators can apply 1,000 times more energy per meter, allowing a vastly more compact design able to fit into a large room.

Jun 27, 2024

Time-compression in electron microscopy: Terahertz light controls and characterizes electrons in space and time

Posted by in categories: nanotechnology, particle physics, quantum physics

Scientists at the University of Konstanz in Germany have advanced ultrafast electron microscopy to unprecedented time resolution. Reporting in Science Advances, the research team presents a method for the all-optical control, compression, and characterization of electron pulses within a transmission electron microscope using terahertz light. Additionally, the researchers have discovered substantial anti-correlations in the time domain for two-electron and three-electron states, providing deeper insight into the quantum physics of free electrons.

Ultrafast electron microscopy is a cutting-edge technique that combines the spatial resolution of traditional electron microscopy with the of ultrafast femtosecond laser pulses. This powerful combination allows researchers to observe atoms and electrons in motion, capturing dynamic processes in materials with unparalleled clarity. By visualizing these rapid events in space and time, scientists can gain deeper insights into the fundamental mechanisms that govern and transitions, helping to create advancements in research fields such as nanotechnology, optics, materials science, and .

Although ultrafast electron microscopy enables, in principle, the observation of atomic and electronic motions on fundamental spatial and temporal scales, capturing these rapid dynamics has remained challenging due to the limitations in electron pulse duration. The current standard electron pulses, lasting about 200 femtoseconds, are too long to resolve many fundamental reaction processes in materials and molecules. Pulses ten times shorter would be required to observe basic reaction paths and collective atomic motions, so-called phonon modes, in real time.

Jun 27, 2024

Engineers produce the world’s first practical Titanium-sapphire laser on a chip

Posted by in categories: computing, neuroscience, quantum physics

As lasers go, those made of Titanium-sapphire (Ti: sapphire) are considered to have “unmatched” performance. They are indispensable in many fields, including cutting-edge quantum optics, spectroscopy, and neuroscience. But that performance comes at a steep price. Ti: sapphire lasers are big, on the order of cubic feet in volume. They are expensive, costing hundreds of thousands of dollars each. And they require other high-powered lasers, themselves costing $30,000 each, to supply them with enough energy to function.

As a result, Ti: lasers have never achieved the broad, real-world adoption they deserve—until now. In a dramatic leap forward in scale, efficiency, and cost, researchers at Stanford University have built a Ti: sapphire laser on a chip. The prototype is four orders of magnitude smaller (10,000x) and three orders less expensive (1,000x) than any Ti: sapphire laser ever produced.

“This is a complete departure from the old model,” said Jelena Vučković, the Jensen Huang Professor in Global Leadership, a professor of electrical engineering, and senior author of the paper introducing the chip-scale Ti: sapphire laser published in the journal Nature.

Jun 26, 2024

The Strange Case of Quantum Time Loops And Testing Backward Time Travel

Posted by in categories: quantum physics, time travel

An exploration of The Strange Case of Quantum Time Loops And Testing Backward Time Travel. My Patreon Page: https://www.patreon.com/johnmichaelgodierMy Event H…

Jun 26, 2024

Raphael Bousso — Is Information Fundamental?

Posted by in categories: particle physics, quantum physics

Watch more interviews on the deep laws of nature: https://shorturl.at/P6tIr Does information work at the deep levels of physics, including quantum theory, undergirding the fundamental forces and particles? But what is the essence of information—describing how the world works or being how the world works. There is a huge difference. Could information be the most basic building block of reality? Support the show with Closer To Truth merchandise: https://bit.ly/3P2ogje Follow us on Instagram for news, giveaways, announcements, and more: https://shorturl.at/dnA39 Raphael Bousso is a theoretical physicist and string theorist. He is a professor at Department of Physics, UC Berkeley. He is known for the proposal of Bousso’s holographic bound, also known as the covariant entropy bound. For members-only benefits, register for a free CTT account today: https://shorturl.at/ajRZ8 Closer To Truth, hosted by Robert Lawrence Kuhn and directed by Peter Getzels, presents the world’s greatest thinkers exploring humanity’s deepest questions. Discover fundamental issues of existence. Engage new and diverse ways of thinking. Appreciate intense debates. Share your own opinions. Seek your own answers.

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