For the study, the team injected and accelerated a mobile impurity into a one-dimensional gas of strongly interacting bosons cooled to near zero.
As the impurity moved through the system, it disturbed the surrounding gas, giving rise to a new emergent quasiparticle with fractional statistics, a 1D anyon, which, until now, had only been observed in two-dimensional systems.
Observing exotic particles
All elementary particles are traditionally classified as either fermions or bosons. Fermions, such as electrons and quarks, follow the Pauli exclusion principle and build the structure of matter, while bosons, like photons and gluons, act as force carriers.
Their fundamental difference lies in what happens when two identical particles are swapped as the wave function of fermions acquires a minus sign, a phase shift of pi, while bosons remain unchanged.
However, in low-dimensional systems, quasiparticles known as anyons exhibit exchange phases between zero and pi, which lie between fermions and bosons. Unlike individual particles, these do not exist independently but arise as excitations within quantum states of matter, similar to phonons arising from solids’ vibrations.
While such exotic behavior had only been detected in 2D environments until now, the novel research is the first to demonstrate that anyon-like behavior can also emerge in a 1D ultracold bosonic gas.
“What’s remarkable is that we can dial in the statistical phase continuously, allowing us to transition from bosonic to fermionic behavior smoothly,” Sudipta Dhar, a PhD student at the University of Innsbruck and one of the leading authors of the study, said.
Redefining quantum future
According to the research team, the experiment opens new doors and possibilities for achieving precise control of exotic quantum states in future research.
“This represents a fundamental advance in our ability to engineer exotic quantum states,” Botao Wang, PhD, from the Université Paris-Saclay in France stated in a press release. “Our modelling directly reflects this phase and allows us to capture the experimental results very well in our computer simulations.”
They believe the findings could have significant implications for quantum computing, particularly in topological quantum computing. This field aims to use the unique properties of anyons to perform error-resistant computations.
“This elegantly simple experimental framework opens new avenues for studying anyons in highly controlled quantum gases,” they concluded. “This discovery marks a pivotal step in the exploration of quantum matter, shedding new light on exotic particle behaviour that may shape the future of quantum technologies.”
The groundbreaking study has been published in the journal Nature.