In quantum mechanics, it’s usually thought there are only two types of particle statistics: fermions and bosons, with an exception for anyons in two dimensions. Another exception, parastatistics, exists in more than two dimensions but is believed to be the same as fermions and bosons.
New research by Rice University physicist Kaden Hazzard and former student Zhiyuan Wang suggests that particles other than bosons and fermions might exist. Their study shows the potential for paraparticles, which were previously thought to be impossible.
“We found that new types of particles we never knew of before are possible,” said Hazzard, associate professor of physics and astronomy.
Bosons can gather in unlimited numbers, while only one fermion can occupy a given state. This is known as the Pauli exclusion principle, shaping the periodic table’s structure.
Scientists observed Pauli crystals for the first time
In the 1930s and 1940s, researchers wondered if other particles could exist. A theory about paraparticles was developed in 1953 but was later thought to be just bosons or fermions in disguise, except for anyons.
The theories from the 1970s assumed conditions that aren’t always true in real systems. Using the Yang-Baxter equation and other math tools, Hazzard and Wang showed that paraparticles could exist and fit within known physics rules. They focused on excitations in condensed matter systems to demonstrate this.
They used advanced math methods to develop models in which paraparticles emerge. When they switch positions, these paraparticles behave differently from fermions and bosons.
These models are just the beginning. They could help understand new phenomena in paraparticle systems and guide experiments to detect them. Future research will focus on developing these theories and observing paraparticles in materials.
Discovering new particles and properties could have applications in quantum information and computing, such as secure communication. However, these applications are still speculative and in their early stages.
Wang said, “To realize paraparticles in experiments, we need more realistic theoretical proposals.”
Journal Reference:
- Wang, Z., Hazzard, K.R.A. Particle exchange statistics beyond fermions and bosons. Nature 637, 314–318 (2025). DOI: 10.1038/s41586-024-08262-7
