GTRI Research Scientist Darian Hartsell makes adjustments to an improved cryogenic vacuum chamber that helps reduce some common noise sources by isolating ions from vibrations and shielding them from magnetic field fluctuations. Credit: Sean McNeil, GTRI

Even very slight environmental noise, such as microscopic vibrations or magnetic field fluctuations a hundred times smaller than Earth’s magnetic field, can be catastrophic for quantum computing experiments with trapped ions.

To address that challenge, researchers at the Georgia Tech Research Institute (GTRI) have developed an improved cryogenic vacuum chamber that helps reduce some common noise sources by isolating ions from vibrations and shielding them from magnetic field fluctuations. The new chamber also incorporates an improved imaging system and a radio frequency (RF) coil that can be used to drive ion transitions from within the chamber.

"There’s a lot of excitement around quantum computing today, and trapped ions are just one of the research platforms available, each with their own benefits and drawbacks," explained Darian Hartsell, a GTRI research scientist who leads the project. "We are trying to mitigate multiple sources of noise in this chamber and make other improvements with one robust new design."

The chamber design is described in a paper published in the journal Applied Physics Letters. Some of the technical improvements developed for the project are already being applied at GTRI and collaborating organizations. This work was done in collaboration with Los Alamos National Laboratory.

Improved cryogenic vacuum chamber that helps reduce some common noise sources by isolating ions from vibrations and shielding them from magnetic field fluctuations. Credit: Sean McNeil, GTRI

Reducing noise and improving fidelity

The goal of the vibration isolation is to reduce the laser amplitude and phase noise when addressing the ions, increasing operational fidelity. The goal of the magnetic field noise reduction is to preserve the coherence of qubits for longer periods of time so researchers can use them for more complex algorithms.

In early testing of the new imaging, the system allowed the researchers to make very high-fidelity measurements in as few as 50 microseconds. Using the RF coil to perform an operation called dynamical decoupling, they were able to increase the ions’ coherence time—the interval during which a qubit retains its quantum properties—from 24(2) milliseconds to 810(30) milliseconds.

The improved system uses magnetic shielding materials within the chamber to keep out magnetic field noise from sources such as elevators in the laboratory building. Other research teams have controlled the magnetic fields by surrounding the entire room holding the test chamber with mu-metal (a nickel-iron ferromagnetic material), but that is costly and cumbersome to install. Using simulations, the researchers realized that installing magnetic shielding within the chamber itself could produce the shielding factor they wanted.

Improved vibration isolation within the chamber reduces the effects of equipment noise from sources such as cooling systems. While vibration mitigation techniques are available in larger quantum systems, the GTRI work was designed to support compact systems being used for basic research. The researchers found they could significantly lower vibration levels by suspending the ion trap within the chamber on posts made from thermally insulating ceramic and plastic materials. The posts separate the four-Kelvin and 40-Kelvin stages of the chamber from the room-temperature portion of the test equipment.

"It was just a really simple back-of-the-envelope heat transfer calculation that Senior Research Engineer Christopher Shappert did to determine that we would have sufficient cooling power and sufficient thermal isolation for us to use these posts," Hartsell said. "But it took a lot of careful design to get the compact magnetic shielding inside the system, along with the vibration control. We were able to successfully implement a lot of complicated improvements."

Advances in fluorescence measurement

Beyond the magnetic shielding and vibration isolation, the GTRI researchers also designed and implemented a new approach for measuring the fluorescence that indicates the state of the trapped ions. The fluorescence is typically collected outside the chamber and directed to a camera or photomultiplier tube (PMT) for photon counting. But this arrangement often limits the light collection.

In their improved system, the GTRI researchers capture light with an in-vacuum objective positioned by a piezoelectrically-driven hexapod structure that allows remote control of the optical components. The higher efficiency of the new capture system allows faster detection, leading to reductions in measurement errors.

The performance of the improved cryogenic vacuum chamber is now being fully characterized to determine detailed performance levels and potentially identify other applications for it. In just 50 microseconds, they are able to detect the state of the ion in a single-shot detection with 99.9963(4)% fidelity. This speed and fidelity surpass previously demonstrated detection for surface-electrode ion taps and would allow researchers to correct errors during a quantum algorithm based on single measurements.

The chamber provides an example of how GTRI quantum researchers are pushing the edge of engineering to improve the results obtained from smaller systems. Those advances, driven by sponsor needs, can then be used by other researchers with larger and more complex systems.

"We’re doing things on a smaller basis and showing the kinds of basic building blocks of quantum science and quantum computing that can be extended to larger systems," said Holly Tinkey, a GTRI senior research scientist who is also working on the project. "We’re showing that there are very tractable engineering approaches to improve performance by thinking and designing cleverly."

Publication details

Darian M. Hartsell et al, Design and characterization of a cryogenic vacuum chamber for ion trapping experiments, Applied Physics Letters (2026). DOI: 10.1063/5.0304948. On arXiv: DOI: 10.48550/arxiv.2510.01557

Citation: New cryogenic vacuum chamber cuts noise for quantum ion trapping (2026, January 21) retrieved 21 January 2026 from https://phys.org/news/2026-01-cryogenic-vacuum-chamber-noise-quantum.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.