greenberger horne zeilinger state

Three voices merging into a single chord. In the physics of quantum materials, this image takes on a literal meaning: three layers of graphene, separated by thin spacers, force electrons and holes from different layers to move as a single fluid.

Quantum communication is like sending a secret letter that tears apart at any attempt to peek. So far, such a letter can only be sent along one road, and that's slow. Scientists have figured out how to send 16 couriers along 16 parallel roads, different frequencies of light, and verified that the letters arrive intact.

A quantum computer isn't just a bunch of qubits: it's a whole city, where each resident is one of the machine's possible states. Residents get to know each other through weak interactions between qubits: if one state can transition to another, a thread of acquaintance is drawn between them.

Seven dancers step onto the stage. They join hands so that any trio or quartet moves in perfect harmony with the rest — no group falls out of the overall rhythm. In the quantum world, this is called an absolutely maximally entangled state (AME for short). It's a perfect knot where every part knows everything about the whole.

A polar molecule is like a tiny dumbbell with opposite charges at its ends. Normally, such particles quickly stick together or fly apart when they meet — electric forces are too strong. But the authors of the work found a way to turn this aggressiveness into a controlled game.

A delicate watermark on wet paper, and a fogged-up glass before your eyes. That's roughly what reading quantum states of light looks like: fragile photon patterns get distorted by losses, and detectors catch only a small fraction of the signal.

If you accelerate an observer to near-light speed, the emptiness around them stops being cold. A thermal glow emerges — an effect predicted in 1976 and named after William Unruh. For earthly accelerations, this glow is vanishingly faint, like a whisper at a rock concert.

Neutrinos are the true ghosts of the microcosm. Nearly massless and chargeless, they pass through planets as if through empty space. But inside each neutrino hides not one particle but three — three 'flavors' (electron, muon, and tau) that constantly morph into one another. This dance is called oscillation.

Three dancers move as one: each feels all the others, and the overall harmony cannot be reduced to individual interactions. This is roughly how three particles behave, born from an electron and positron collision at the speed of light. They are a top quark, its antiparticle, and a Z boson.

Two dice lie in different rooms. If they are 'entangled,' a roll of one instantly determines the outcome of the other — even at a distance. In the quantum world, such a link is called steering: one party, by performing measurements on their side, seems to dictate the state of the partner.

Any measuring device is spoiled by quantum noise — the chaotic jitters of elementary particles. To tame it, physicists used a trick on calcium fluoride molecules, much like squeezing a balloon: press in one spot, and it bulges in another.

A soap bubble hangs in the air, and its shape already contains everything needed to calculate the internal tension. A similar principle worked in a new study on quantum gravity. Physicists took a closed surface, an analog of such a bubble, and specified a few numbers on it: for example, the electric field strength and the curvature.

Two entangled photons fly apart in opposite directions but continue to behave as a single whole: measuring one instantly determines the state of the other. That's quantum entanglement. But sometimes it resembles a seasoned spy — leaving no traces detectable by ordinary checks.

A quantum computer is like an orchestra where each musician plays their part, but if one hits a wrong note, the melody falls apart. Errors arise constantly: from thermal jitter, from imperfect instruments. To keep the symphony going, you need a "conductor" who hears the off-key notes and corrects them on the fly.

Light bends around massive bodies: this has been known since Einstein's time. But what if gravity itself is not a smooth fabric of space but a stream of tiny carrier particles? Then a beam passing near a particle should not just bend but enter into a special quantum relationship with it. This relationship is called entanglement.

Two tiny dust grains hover at the crossing of laser beams. Each is held by its own 'tweezer'—a focused beam that keeps the particle from falling. Inside a mirrored cavity, light bounces between the walls, and its oscillations are coupled to the trembling of the grains.

Eighteen tiny cells line up in two rows on a piece of germanium. Each cell is a quantum dot — a trap for a single electron whose spin acts as a qubit. Previously, such systems could only be assembled in small numbers, but here we have an entire lattice working as a single ensemble.

Two particles flying apart in opposite directions behave as a single whole: measuring one instantly determines the state of the other. Such quantum entanglement has long been known for light particles, but now it has been observed for the first time in heavy Z bosons — the carriers of the weak force.

Ordinary light is like a crowd in a square: each photon moves on its own, bumping into others and scattering. But in some media, photons start running together like a pack of dogs: they bunch up. Scientists have built a random fiber laser where light particles gather into especially dense clusters.

Picture heavy balls resting on a stretchy trampoline: each one sinks into the fabric, and their dents overlap, causing the balls to roll toward each other. This analogy helps explain how gravity — the curvature of spacetime — links massive particles. But what if you bring gravity and quantum mechanics together?

At the Large Hadron Collider, by accelerating particles to nearly light speeds, top quarks are created — the heaviest building blocks of the Standard Model. They live for vanishingly small fractions of a second but manage to exhibit complex quantum connections.

Fragile as ice in a furnace, quantum entanglement usually perishes from the slightest heat. Near a black hole, where space is twisted by Einstein's gravity and Hawking radiation Hawking's heats things up, any bond should be destroyed.

A powerful laser strikes a semiconductor, and it responds with light at many frequencies, like a string sounding a chorus of overtones. Previously, this was used in spectroscopy to observe ultrafast processes. But now physicists have noticed: the overtones are not independent; they behave as if connected by invisible threads.

For a long time, physicists were certain: quantum entanglement requires direct quantum contact. A new study refutes this. Two microscopic magnetic particles, connected only by a classical spring, successfully become entangled.

In the quantum world, a collision between particles doesn't destroy their individuality but ties them into an inseparable knot: internal states and motions become intertwined like threads in an intricate tapestry.

Quantum entanglement is a special connection between particles: they affect each other instantly, even across light-years. For a long time, it was believed that strong acceleration destroys this bond.

Quantum computers use GKP states, dreamed up by Alexei Kitaev, John Preskill, and Daniel Gottesman. Their hallmark is built-in stabilizer checks that catch errors. For a long time, it was believed that a successful check guaranteed a nearly perfect state. Alas, it's an illusion.

The idea of quantum teleportation was proposed by Charles Bennett and realized by Anton Zeilinger. It uses entanglement — when two particles are in sync, like two sheets of paper that instantly copy the same drawing. But earlier, the "ink" would blur, ruining the blueprint.

There's always a risk that someone will peek at your ballot during an election. Physicists have come up with a solution: anonymous voting safeguarded not by people, but by the laws of nature. Their 'magic ballot box' operates with light particles — photons.

Regular quantum communication is like a postal service that sends letters strictly one at a time. If the route is long, you have to wait an indecently long time for a reply. Physicists sped up the process by dispatching ten 'postal trucks' — light pulses — into a single optical fiber, but in different time windows.

Picture an orchestra of 120 musicians playing in perfect unison — one false note and the harmony crumbles. That's the metaphor for a record-breaking quantum ensemble. Physicists have for the first time entangled 120 superconducting qubits, the building blocks of future computers.

Physicists have for the first time created a trio of photons entangled as a single whole, not just pairwise. To achieve this, a special chip was cooled to a temperature hundreds of times lower than that of deep space — any noise threatened to destroy the fragile link.

In a laboratory at Purdue University, a laser beam strikes a crystal of hexagonal boron nitride, and in response, a single point of light flashes. This is not just luminescence; it is a signal from a spin defect, a pair of electron spins, one of which is coupled to a carbon-13 nuclear spin.

In an accelerator, two Higgs particles collide. For a fleeting moment, their fates intertwine, then separate, carrying away information about the encounter.