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Archive for the ‘quantum physics’ category: Page 152

May 8, 2023

The realization of a continuous time crystal based on a photonic metamaterial

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

A time crystal, as originally proposed in 2012, is a new state of matter in which the particles are in continuous oscillatory motion. Time crystals break time-translation symmetry. Discrete time crystals do so by oscillating under the influence of a periodic external parametric force, and this type of time crystal has been demonstrated in trapped ions, atoms and spin systems.

Continuous time crystals are more interesting and arguably more important, as they exhibit continuous time-translation symmetry but can spontaneously enter a regime of periodic motion, induced by a vanishingly small perturbation. It is now understood that this state is only possible in an open system, and a continuous quantum-time-crystal state has recently been observed in a quantum system of ultracold atoms inside an optical cavity illuminated with light.

In a paper published in Nature Physics, researchers at University of Southampton in the U.K. showed that a classical metamaterial nanostructure can be driven to a state that exhibits the same key characteristics of a continuous time crystal.

May 8, 2023

Quantum computers may hold the secret to achieving absolute zero, finds study

Posted by in categories: computing, quantum physics

According to the rules of thermodynamics, you need infinite time or energy to achieve absolute zero. But a new study says there is another way.

Light, sound, and heat are all types of energy around us. Thermodynamics is a branch of science that helps us understand how energy moves between objects. According to the third law of thermodynamics, it is impossible to cool any object to-273.15 degrees C (or absolute zero), which is the lowest temperature possible.

Now a research team from the Vienna University of Technology in Austria has found a way to cool an object to absolute zero. The study published in PRX Quantum demonstrates this alternate route using quantum computing.

May 8, 2023

Electron re-collision tracked in real time

Posted by in categories: particle physics, quantum physics

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The motion of an electron in a strong infrared laser field is tracked in real time by means of a novel method developed by MPIK physicists and applied to confirm quantum-dynamics theory by cooperating researchers at MPI-PKS. The experimental approach links the absorption spectrum of the ionizing extreme ultraviolet pulse to the free-electron motion driven by the subsequent near-infrared pulse. Their paper is published in the journal Physical Review Letters.

For this experimental scheme, the classical description of the electron motion is justified even though it is a quantum object. In the future, the new method demonstrated here for helium can be applied to more such as larger atoms or molecules for a broad range of intensities.

Continue reading “Electron re-collision tracked in real time” »

May 8, 2023

Tweezers in Three Dimensions

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

A new kind of 3D optical lattice traps atoms using focused laser spots replicated in multiple planes and could eventually serve as a quantum computing platform.

Researchers have produced 3D lattices of trapped atoms for possible quantum computing tasks, but the standard technology doesn’t allow much control over atom spacing. Now a team has created a new type of 3D lattice by combining optical tweezers—points of focused light that trap atoms—with an optical phenomenon known as the Talbot effect [1]. The team’s 3D tweezer lattice has sites for 10,000 atoms, but with some straightforward modifications, the system could reach 100,000 atoms. Such a large atom arrangement could eventually serve as a platform for a quantum computer with error correction.

3D optical lattices have been around for decades. The standard method for creating them involves crossing six laser beams to generate a 3D interference pattern that traps atoms in either the high-or low-intensity spots (see Synopsis: Pinpointing Qubits in a 3D Lattice). These cold-atom systems have been used as precision clocks and as models of condensed-matter systems. However, the spacing between atoms is fixed by the wavelength of the light, which can limit the control researchers have over the atomic behavior.

May 7, 2023

Google is testing a Chrome browser that adds post-quantum encryption

Posted by in categories: encryption, quantum physics, security

Google is using its enormous Chrome browser testing base to help examine the prospect of continuing the security of the digital age into the uncertainty of the quantum one.

May 7, 2023

Breakthrough experiment proves light travels in both space and time

Posted by in categories: innovation, quantum physics

Physicists have achieved a significant milestone in the world of quantum physics by recreating the famous double-slit experiment in time.

May 7, 2023

Quantum lidar prototype acquires real-time 3D images while fully submerged underwater

Posted by in categories: engineering, particle physics, quantum physics, security

For the first time, researchers have demonstrated a prototype lidar system that uses quantum detection technology to acquire 3D images while submerged underwater. The high sensitivity of this system could allow it to capture detailed information even in extremely low-light conditions found underwater.

“This technology could be useful for a wide range of applications,” said research team member Aurora Maccarone, a Royal Academy of Engineering research fellow from Heriot-Watt University in the United Kingdom. “For example, it could be used to inspect underwater installations, such as underwater wind farm cables and the submerged structure of the turbines. Underwater can also be used for monitoring or surveying submerged archaeology sites and for security and defense applications.”

Continue reading “Quantum lidar prototype acquires real-time 3D images while fully submerged underwater” »

May 7, 2023

Physicists Discovered a Quantum Trick For Reaching Absolute Zero

Posted by in categories: particle physics, quantum physics

The state of perfect stillness known as absolute zero is one of the Universe’s impossible achievements. As close as we can get, the laws of physics will always prevent us from hitting thermal rock bottom.

An international team of researchers has now identified a new theoretical route to reach the mythical mark of zero Kelvin, or-273.15 degrees Celsius (−459.67 degrees Fahrenheit). No, it’s not more likely to break any laws and remove every last shimmer of heat, but the framework could inspire new ways of exploring matter at low temperatures.

As a consequence of the third law of thermodynamics, the removal of increments of heat energy from a group of particles to cool them to absolute zero will always take an infinite number of steps. As such, it requires an infinite amount of energy to achieve. Quite the challenge.

May 7, 2023

Zeroing in on a fundamental property of the proton’s internal dynamics

Posted by in categories: particle physics, quantum physics

Inside the proton are elementary particles called quarks. Quarks and protons have an intrinsic angular momentum called spin. Spin can point in different directions. When it is perpendicular to the proton’s momentum, it is called a transverse spin. Just like the proton carries an electric charge, it also has another fundamental charge called the tensor charge. The tensor charge is the net transverse spin of quarks in a proton with transverse spin.

The only way to obtain the charge from is using the theory of quantum chromodynamics (QCD) to extract the “transversity” function. This universal function encodes the difference between the number of quarks with their spin aligned and anti-aligned to the proton’s spin when it is in a transverse direction. Using state-of-the-art data science techniques, researchers recently made the most precise empirical determination of the tensor charge.

Due to the phenomenon known as confinement, quarks are always bound in the proton or other hadrons (particles with multiple quarks). The challenge is to connect the theory of interactions (QCD) to experimental measurements of high-energy collisions involving hadrons.

May 7, 2023

Wonder Material Graphene Just Broke Another Major Record in Physics

Posted by in categories: biotech/medical, quantum physics

Graphene is a special material. Among its many talents, it can act as a superconductor, generate a super-rare form of magnetism, and unlock entirely new quantum states.

Now graphene has another amazing credit: it can record levels of magnetoresistance without a need to push the temperature down towards absolute zero.

High magnetoresistance – a material’s ability to change its electrical resistance in response to a magnetic field – is relatively rare, yet materials that can shift their properties in this fashion are useful in computers, cars, and medical equipment.