Quantum Computing’s Dynamic Duo: Ion Trap Meets Single-Photon Detector

Researchers have developed a combined ion trap and single-photon detector device to improve quantum computing systems. The new device overcomes the issue of competing requirements between the ion trap and photon detector by incorporating an aluminum barrier at the bottom of the detector, allowing for large voltages to be used without disrupting the detector’s performance. This NIST innovation has been published in Applied Physics Letters. Credit: NIST

A combined ion trap and single-photon detector device has been developed to improve quantum computing systems, overcoming previous challenges in tracking multiple ions for increased processing power. The device features an aluminum barrier to balance the needs of both the ion trap and photon detector.

We’re building the tools to trap ions and watch them glow (or not).

The art-deco-esque device shown here is a combined trap for ions (charged atoms) and detector for individual photons (particles of light). When you hold an ion in place and hit it with a laser, depending on its quantum state, the ion will either glow and emit photons … or it will do nothing and stay in the dark.

But we aren’t going through this process for a 50/50 chance at a light show.

The glow-or-no-glow odds for ions have a significant impact on the future of computing. Quantum computers can assign values to those two quantum states, similar to the 0s and 1s in the binary system that our classical computers use to operate.

The best practice thus far has been to use a large, custom-built microscope lens and bulky single-photon detector to identify whether a trapped ion glows or not. That’s sufficient on a small scale, but technical problems arise when a quantum computing system needs to keep track of many ions at once (for added processing power). Ions can be out of view, or the image can get distorted.

Not only do NIST researchers have a potential alternative, but they’ve just made it much more realistic.

Our combined ion trap/single-photon detector takes away the need for bulky equipment and maintains the potential for a clear view of all the ions in the system.

Previous iterations faced the challenge of competing personalities. The trap needed large voltages on its electrodes to hold ions in place, while the detector was much more delicate and preferred an environment without large electrical signals.

Now, our team has crafted a version with an aluminum barrier around the bottom of the detector. The ion trap can use large voltages, and the detector can keep its peace. Get the specifics on this NIST innovation in the research paper, published in Applied Physics Letters.

Reference: “Trap-integrated superconducting nanowire single-photon detectors with improved rf tolerance for trapped-ion qubit state readout” by Benedikt Hampel, Daniel H. Slichter, Dietrich Leibfried, Richard P. Mirin, Sae Woo Nam and Varun B. Verma, 24 April 2023, Applied Physics Letters.
DOI: 10.1063/5.0145077