Researchers have demonstrated a breakthrough boson sampling method using ultracold atoms in optical lattices

JILA researcher, National Institute of Standards and Technology (NIST) physicist, physics professor Adam Kaufman and his team at the University of Colorado Boulder, as well as NIST collaborators, demonstrated a new method of cross laser beam lattice sampling using ultracold atoms for boson sampling in two-dimensional optics. This study, recently published in the journal Nature, marks a significant leap in past achievements in computer simulation or photons.

Applying optical tweezers to large-scale Hubbard systems
Researchers used cutting-edge technology, including optical tweezers and advanced cooling methods, to prepare specific patterns of up to 180 strontium atoms in a lattice of 1000 points. By minimizing the motion of atoms and ensuring they remain in the lowest energy state, the team reduced noise and decoherence, which are common challenges in quantum experiments.

Kaufman said, "Optical tweezers have achieved groundbreaking experiments in multibody physics, typically used to study interacting atoms, where atoms are fixed in space and interact over long distances." "However, when particles can both interact and tunnel, and quantum mechanics spreads in space, a fundamental class of multibody problems arises - the so-called 'Hubbard' system. In the early stages of establishing this experiment, our goal was to apply this tweezer paradigm to large-scale Hubbard systems - this article marks the first realization of this vision."

Confirm high fidelity through scaling testing
Due to the complexity of boson sampling, it is not feasible to directly verify the correct sampling task of 180 atomic experiments. To overcome this issue, researchers sampled atoms of different scales and compared the measurement results with simulations of reasonable error models involving intermediate scale experiments.

"We tested with two atoms and we have a good understanding of what is happening. Then, at an intermediate scale where we can still simulate things, we can compare our measurement results with simulations involving reasonable error models in our experiments. On a large scale, we can continuously change the difficulty of the sampling task by controlling the distinguishability of atoms and confirm that there are no major issues," said Aaron Young, the first author and former JILA graduate student.

This work demonstrates the high-quality and programmable preparation, evolution, and detection of atoms in the lattice, which can be applied to atomic interactions, opening up new methods for simulating and studying the behavior of real and poorly known quantum materials.

Source: Laser Net