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Category: quantum physics – Page 4

Simulating the Hawking effect and other quantum field theory predictions with polariton fluids

Quantum field theory (QFT) is a physics framework that describes how particles and forces behave based on principles rooted in quantum mechanics and Albert Einstein’s special relativity theory. This framework predicts the emergence of various remarkable effects in curved spacetimes, including Hawking radiation.

Hawking radiation is the thermal radiation theorized to be emitted by close to the (i.e., the boundary around a black hole after which gravity becomes too strong for anything to escape). As ascertaining the existence of Hawking radiation and testing other QFT predictions in space is currently impossible, physicists have been trying to identify that could mimic aspects of curved spacetimes in experimental settings.

Researchers at Sorbonne University recently identified a new promising experimental platform for simulating QFT and testing its predictions. Their proposed QFT simulator, outlined in a paper published in Physical Review Letters, consists of a one-dimensional quantum fluid made of polaritons, quasiparticles that emerge from strong interactions between photons (i.e., light particles) and excitons (i.e., bound pairs of electrons and holes in semiconductors).

A strange quantum battery concept reveals the second law of entanglement

For more than a century, the laws of thermodynamics have helped us understand how energy moves, how engines work, and why time seems to flow in one direction. Now, researchers have made a similarly powerful discovery, but in the strange world of quantum physics.

Scientists have shown for the first time that entanglement, the mysterious link between quantum particles, can be reversibly manipulated just like heat or energy in a perfect thermodynamic cycle.

The researchers support their findings using a novel concept called an entanglement battery, which allows entanglement to flow in and out of quantum systems without being lost, much like a regular battery stores and supplies energy.

Famous double-slit experiment holds up when stripped to its quantum essentials

MIT physicists have performed an idealized version of one of the most famous experiments in quantum physics. Their findings demonstrate, with atomic-level precision, the dual yet evasive nature of light. They also happen to confirm that Albert Einstein was wrong about this particular quantum scenario.

The experiment in question is the double-slit experiment, which was first performed in 1801 by the British scholar Thomas Young to show how light behaves as a wave. Today, with the formulation of quantum mechanics, the double-slit experiment is now known for its surprisingly simple demonstration of a head-scratching reality: that light exists as both a particle and a wave. Stranger still, this duality cannot be simultaneously observed. Seeing light in the form of particles instantly obscures its wave-like nature, and vice versa.

The original experiment involved shining a beam of light through two parallel slits in a screen and observing the pattern that formed on a second, faraway screen. One might expect to see two overlapping spots of light, which would imply that light exists as particles, a.k.a. photons, like paintballs that follow a direct path. But instead, the light produces alternating bright and dark stripes on the screen, in an interference pattern similar to what happens when two ripples in a pond meet. This suggests light behaves as a wave. Even weirder, when one tries to measure which slit the light is traveling through, the light suddenly behaves as particles and the interference pattern disappears.

New quantum visualisation techniques could accelerate the arrival of

Scientists have been studying a fascinating material called uranium ditelluride (UTe₂), which becomes a superconductor at low temperatures.

Superconductors can carry electricity without any resistance, and UTe₂ is special because it might belong to a rare type called spin-triplet superconductors. These materials are not only resistant to magnetic fields but could also host exotic quantum states useful for future technologies.

However, one big mystery remained: what is the symmetry of UTe₂’s superconducting state? This symmetry determines how electrons pair up and move through the material. To solve this puzzle, researchers used a highly sensitive tool called a scanning tunneling microscope (STM) with a superconducting tip. They found unique signals—zero-energy surface states—that helped them compare different theoretical possibilities.

Their results suggest that UTe₂ is a nonchiral superconductor, meaning its electron pairs don’t have a preferred handedness (like left-or right-handedness). Instead, the data points to one of three possible symmetries (B₁ᵤ, B₂ᵤ, or B₃ᵤ), with B₃ᵤ being the most likely if electrons scatter in a particular way along one axis.

This discovery brings scientists closer to understanding UTe₂’s unusual superconducting behavior, which could one day help in designing more robust quantum materials.

UTe₂ currently operates at very low temperatures (~1.6 K), so raising its critical temperature is a major goal.

Scaling up production and integrating it into devices will require further material engineering.

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