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Archive for the ‘quantum physics’ category: Page 253

Jul 2, 2023

We’re on the brink of the biggest changes to computing’s DNA and it’s not just quantum that’s coming

Posted by in categories: biotech/medical, computing, mathematics, quantum physics

Computers are built around logic: performing mathematical operations using circuits. Logic is built around things such as Adders—not the snake; the basic circuit that adds together two numbers. This is as true of today’s microprocessors as all those going back to the very beginning of computing history. You could go back to an abacus and find that, at some fundamental level, it does the same thing as your shiny gaming PC. It’s just much, much less capable.

Nowadays, processors can do a lot of mathematical calculations using any number of complex circuits in a single clock. And a lot more than just add two numbers together, too. But to get to your shiny new gaming CPU, there has been a process of iterating on the classical computers that came before, going back centuries.

Jul 2, 2023

Comprehensive Overview of Progress Achieved in the Field of Quantum Teleportation

Posted by in categories: computing, quantum physics

A team led by Academician Prof. Guangcan Guo from the Chinese Academy of Sciences (CAS) provides a comprehensive overview of the progress achieved in the field of quantum teleportation. The team, which includes Prof. Xiaomin Hu, Prof. Yu Guo, Prof. Biheng Liu, and Prof. Chuanfeng Li from the University of Science and Technology of China (USTC), CAS, was invited to publish a review paper on quantum teleportation in the peer-reviewed scientific journal Nature Review Physics. The paper was officially released online on May 24.

As one of the most important protocols in the field of quantum information, quantum teleportation has attracted great attention since it was proposed in 1993. Through entanglement distribution and Bell-state measurement, quantum teleportation enables the nonlocal transmission of an unknown quantum state, which has deepened the understanding of quantum entanglement. More importantly, quantum teleportation can effectively overcome the distance limitation of direct transmission of quantum states in quantum communication, as well as realize long-range interactions between different quantum bits in quantum computing.

Performing computation using quantum-mechanical phenomena such as superposition and entanglement.

Jul 1, 2023

Quantum biology: Your nose and house plant are experts at particle physics

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

Quantum physics governs the world of the very small and that of the very cold. Your dog cannot quantum-tunnel her way through the fence, nor will you see your cat exhibit wave-like properties. But physics is funny, and it is continually surprising us. Quantum physics is starting to show up in unexpected places. Indeed, it is at work in animals, plants, and our own bodies.

We once thought that biological systems are too warm, too wet, and too chaotic for quantum physics to play any part in how they work. But it now seems that life is employing feats of quantum physics every day in messy, real-world systems, including quantum tunneling, wave-particle duality, and even entanglement. To see how it all works, we can start by looking right inside our own noses.

The human nose can distinguish over one trillion smells. But how exactly the sense of smell works is still a mystery. When a molecule referred to as an odorant enters our nose, it binds to receptors. Initially, the prevailing theory held that these receptors used the shape of the odorants to differentiate smells. The so-called lock and key model suggests that when an odorant finds the right receptor, it fits into it and triggers a specific smell. But the lock and key model ran into trouble when tested. Subjects were able to tell two scents apart, even when the odorant molecules were identical in shape. Some other process must be at work.

Jul 1, 2023

Quantum Breakthrough: The First Ever Realization of a Laughlin State

Posted by in categories: particle physics, quantum physics

The discovery of quantum Hall effects during the 1980s unveiled new forms of matter termed “Laughlin states”, named after the American Nobel laureate who successfully characterized them theoretically.

These exotic states uniquely appear in two-dimensional materials, under extremely cold conditions, and when subjected to a profoundly strong magnetic field. In a Laughlin state, electrons constitute an unusual liquid, where each electron dances around its congeners while avoiding them as much as possible.

Exciting such a quantum liquid generates collective states that physicists associate with fictitious particles, whose properties drastically differ from electrons: these “anyons” carry a fractional charge (a fraction of the elementary charge) and they surprisingly defy the standard classification of particles in terms of bosons or fermions.

Jul 1, 2023

Chaining Atoms Together Yields Quantum Storage

Posted by in categories: particle physics, quantum physics

Year 2022 😗😁


Data stored in spin states of ytterbium atoms can be transferred to surrounding atoms in a crystal matrix.

Jun 30, 2023

Engineers develop first-of-its-kind integrated optical isolator

Posted by in categories: computing, quantum physics

An optical isolator developed at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) could drastically improve optical systems for many practical applications.

All —used for telecommunications, microscopy, imaging, quantum photonics, and more—rely on a laser to generate photons and . To prevent those lasers from damage and instability, these systems also require isolators, components that prevent light from traveling in undesired directions. Isolators also help cut down on signal noise by preventing light from bouncing around unfettered. But conventional isolators have been relatively bulky in size and require more than one type of material to be joined together, creating a roadblock to achieving enhanced performance.

Now, a team of researchers led by electrical engineer Marko Lončar at SEAS has developed a method for building a highly-efficient integrated isolator that’s seamlessly incorporated into an made of lithium niobate. Their findings are reported in Nature Photonics.

Jun 29, 2023

Scientists edge toward scalable quantum simulations on a photonic chip

Posted by in categories: computing, quantum physics, space

Scientists have made an important step toward developing computers advanced enough to simulate complex natural phenomena at the quantum level. While these types of simulations are too cumbersome or outright impossible for classical computers to handle, photonics-based quantum computing systems could provide a solution.

A team of researchers from the University of Rochester’s Hajim School of Engineering & Applied Sciences developed a new chip-scale optical quantum system that could help make such a system feasible. The team, led by Qiang Lin, a professor of electrical and engineering and optics, published their findings in Nature Photonics.

Lin’s team ran the simulations in a synthetic space that mimics the physical world by controlling the frequency, or color, of quantum entangled photons as time elapses. This approach differs from the traditional photonics-based computing methods in which the paths of photons are controlled, and also drastically reduces the physical footprint and resource requirements.

Jun 29, 2023

Quantum computing could get boost from discovery of Q-silicon

Posted by in categories: computing, quantum physics

Researchers at North Carolina State University have discovered a new distinct form of silicon called Q-silicon which, among other interesting properties, is ferromagnetic at room temperature. The findings could lead to advances in quantum computing, including the creation of a spin qubit quantum computer that is based on controlling the spin of an electron.

“The discovery of Q-silicon having robust ferromagnetism will open a new frontier in atomic-scale, spin-based devices and functional integration with nanoelectronics,” said Jay Narayan, the John C. Fan Family Distinguished Chair in Materials Science and corresponding author of a paper describing the work published in Materials Research Letters.

Ferromagnetism in materials outside of and has excited scientists worldwide for a long time. This is because spin-polarized electrons can be used to process and store information with atomic resolution. However, materials with even numbers of electrons, such as carbon and silicon, without unpaired spins were not considered seriously in terms of bulk ferromagnetism. The dangling bonds in bulk carbon and silicon materials usually reconstruct and eliminate sources of unpaired electrons.

Jun 29, 2023

InAs-Al hybrid devices passing the topological gap protocol

Posted by in categories: materials, quantum physics

Topological phases of matter can enable highly stable qubits with small footprints, fast gate times, and digital control. These hardware-protected qubits must be fabricated with a material combination in which a topological phase can reliably be induced. The challenge: disorder can destroy the topological phase and obscure its detection. This paper reports on devices with low enough disorder to pass the topological gap protocol, thereby demonstrating gapped topological superconductivity and paving the way for a new stable qubit.

Jun 29, 2023

Study shows hexagonal boron nitride has potential to replace diamond as quantum sensing material

Posted by in categories: materials, quantum physics

Diamond has long been the go-to material for quantum sensing due to its coherent nitrogen-vacancy centers, controllable spin, sensitivity to magnetic fields, and ability to be used at room temperature. With such a suitable material so easy to fabricate and scale, there’s been little interest in exploring diamond alternatives.

But this GOAT of the quantum world has one Achilles Heel—It’s too big. Just as an NFL linebacker is not the best sportsperson to ride in the Kentucky Derby, diamond is not an ideal material when exploring quantum sensors and . When diamonds get too small, the super-stable defect it’s renowned for begins to crumble. There is a limit at which diamond becomes useless.

HBN has previously been overlooked as a quantum sensor and a platform for . This changed recently when a number of new defects were discovered that are shaping up to be compelling competitors to diamond’s nitrogen vacancy centers.