A quantum leap forward for qubit encoding

Optical tweezers, which trap ultracold atoms in highly focused laser beams, have emerged as a preferred tool for advancing quantum computing thanks to their connectivity and scalability. In particular, strontium (Sr) boasts a conducive electronic structure that enables extreme precision and allows for effective qubit encoding. But many existing setups typically use 2D magneto-optical traps, which can suffer from limited vacuum isolation and inherent heating.

Venderbosch et al. developed an apparatus with a single laser beam and a 5x5 grid of tweezers, each of which holds a single atom, that employs a deflection stage to isolate the hot, 420 C Sr oven from the cold atoms loaded into the grid.

“We need cold atoms at micro-Kelvin temperatures because only then is their kinetic energy low enough to stay inside the tweezers,” said author Rianne Lous.

The novel setup also features a laser system with fiber optic splitters, multiplexers and acousto-optic modulators, and frequency comb technology to make it as compact as possible. The lasers themselves are ultimately kept stable using a frequency source about 100 kilometers away at the Dutch Metrology Institute, which distributes signals over optical fiber to the laboratory.

In addition to providing guidance for the development of new Sr tweezer setups, the innovation will become part of a multi-hardware quantum technology platform that offers users the chance to try out different quantum computers and simulators.

“Neutral atom quantum computers are among the fastest growing platforms with record amounts of qubits and competitive coherence times,” said Lous. “The end goal is to make a quantum computer openly accessible to the public by offering a user-friendly platform and a high-level programming language.”

Source: “A robust strontium tweezer apparatus for quantum computing,” by Marijn Venderbosch, Rik van Herk, Zhichao Guo, Jeśus del Pozo Mellado, Max Festenstein, Deon Janse van Rensburg, Ivo Knottnerus, Yu Chih Tseng, Alexander Urech, Robert Spreeuw, Florian Schreck, Rianne Lous, Edgar Vredenbregt, and Servaas Kokkelmans, AIP Advances (2026). The article can be accessed at https://doi.org/10.1063/5.0324304 .

This paper is part of the Quantum Information Science & Technologies Collection, learn more here .