Your desk is It is composed of individual, different atoms, but from a distance, its surface looks very smooth. This simple idea is the core of all our physical world models. We can describe what is happening as a whole without getting caught up in the complex interactions between each atom and electron.
Therefore, when a new theoretical state of matter is discovered, its microscopic features stubbornly exist on all scales, and many physicists refuse to believe its existence.
“When I first heard about fractals, I said it couldn’t be true because it completely violated my prejudice against the way the system behaves,” said Nathan Seberg, A theoretical physicist at the Institute for Advanced Study in Princeton, New Jersey. “But I was wrong. I realized I was living in denial all the time.”
Theoretical Possibilities of Fractals Surprised physicists in 2011Recently, these strange states of matter have been guiding physicists to new theoretical frameworks that can help them solve some of the most difficult problems in fundamental physics.
Fractals are quasi-particles-particle-like entities that emerge from the complex interactions between many elementary particles in a material.But fractons are even compatible with Other strange quasiparticles, Because they are completely immobile or can only move in a limited way. Nothing in their environment can prevent fractal movement; on the contrary, it is their inherent property. This means that the microstructure of fractals affects their long-distance behavior.
“This is totally shocking. For me, this is the strangest phase of matter,” said Xie Chen, A condensed matter theorist at California Institute of Technology.
Part of the particles
in 2011, Zheng Wanxia, Was a graduate student at the California Institute of Technology, looking for an unusually stable material phase Can be used to protect quantum memory, Even at room temperature. Using computer algorithms, he discovered a new theoretical stage, which was later called the Haah code. Because of the strange immovable quasi-particles that make up it, this phase quickly attracted the attention of other physicists.
They look like a small part of the particle alone, and can only move in combination.Soon, more theoretical phases with similar characteristics were discovered, so in 2015 Haah and Sagar Vijay and Liang Fu—Coined the term “fractons” For the strange part of quasi-particles. (Previously an overlooked Thesis by Claudio Chamon It is now due to the initial discovery of fractal behavior. )
To understand the special features of the fractal phase, consider a more typical particle, such as an electron, which moves freely in the material. The strange but used way for some physicists to understand this kind of movement is that electrons move because space is full of electron-positron pairs, which suddenly appear and disappear in an instant. The appearance of such a pair makes the positron (the oppositely charged antiparticle of the electron) sit on top of the original electron, and then they will annihilate. This leaves the electron in the electron pair, which is displaced from the original electron. Since two electrons cannot be distinguished, we can only see one electron in motion.
Now on the contrary, imaginary particles and antiparticles cannot emerge from the vacuum, but can only be their squares. In this case, a square may appear, so an antiparticle is on top of the original particle, eliminating that corner. Then the second square pops out of the vacuum, annihilating one side of the first square. This leaves the other side of the second square, also composed of a particle and an antiparticle. The resulting movement is the horizontal movement of the particle-antiparticle pair along a straight line. In this world—an example of a fractal stage—the movement of a single particle is restricted, but a pair of particles can move easily.
The Haah code takes this phenomenon to its extreme: particles can only move when new particles are summoned in an endless repeating pattern called fractals. Suppose you arrange four particles in a square, but when you zoom in on each corner, you will find another square composed of four particles, which are close to each other. Zoom into the corner again and you will find another square, and so on. To achieve such a structure in a vacuum requires so much energy that it is impossible to move this type of debris. This allows very stable qubits (bits of quantum computing) to be stored in the system because the environment cannot destroy the delicate state of the qubits.