Reducing Ion Heating in Quantum Computing: A Novel 3D-Printed Micro Ion Trap with Skeleton Structure

TL;DR

Electric-field-induced motional heating limits scalability in trapped-ion quantum computing. The authors propose a hollow, skeleton-like, 3D-printed ion trap that minimizes electrode surface area near the ion while preserving harmonic confinement, and they quantify heating using a patch-potential framework. The results show a >50% reduction in total heating relative to a conventional blade trap, with a spatial map revealing dominant contributions from surfaces within a few hundred micrometers; axial heating exhibits a distinct hotspot at ~110 μm due to field-directionality, which can be mitigated through targeted electrode reconfiguration. Together, these findings establish a practical, geometry-driven pathway to low-noise, scalable trapped-ion devices enabled by additive manufacturing, and they provide design rules linking ion–electrode geometry to noise suppression.

Abstract

Electric-field-induced ion heating is a major obstacle in scalable trapped-ion quantum computing. We present a theoretical study of a novel 3D-printed ion trap with a skeleton electrode structure, designed to reduce heating by minimizing surface area near the ion. Compared to a conventional blade trap with identical confinement parameters, the skeleton trap achieves over 50% reduction in total heating rate. Patch-by-patch analysis reveals that heating is dominated by surfaces within 500 μm of the ion. For axial motion, the peak heating occurs approximately 110 μm away due to electric field directionality. We demonstrate that minor geometric optimization, in which the electrode gaps are realigned with these hotspots, can further suppress heating despite the associated increase in surface area. A linear relationship between ion-to-electrode distance and peak heating location is also established. These results highlight the potential of 3D-printed electrode designs for achieving both strong confinement and reduced noise in future quantum systems.

Figures (7)

• Figure 1: Schematic representations of the 3D-printed ion trap geometries analyzed in this work. (a) Proposed 3D-printed ion trap with a skeleton electrode structure designed to reduce electric-field noise. The wire-frame electrodes have a diameter of 20 $\mu$m. (b) Side view of the 3D-printed trap showing a 400 $\mu$m distance between opposing electrodes, corresponding to an ion-to-electrode distance of 200 $\mu$m. (c) Zoom-in view of the segmented electrode “teeth” structure. Each electrode tooth is 170 $\mu$m wide, with a 9 $\mu$m gap between adjacent teeth. (d) Simulated steady-state temperature distribution of the trap under 600 V RF amplitude and 30 MHz drive frequency, showing a maximum temperature near 60 $^{\circ}$C. In all subfigures, blue elements denote RF electrodes and yellow elements denote DC electrodes. The ion is located at the geometric center of the trap, equidistant from the nearest electrode surfaces.
• Figure 2: RF trap stability and secular frequency characteristics for the 3D-printed and blade traps. (a) Ratio of the radial secular frequency $\omega$ to the RF drive frequency $\Omega_{RF}$ as a function of $\Omega_{RF}$, calculated for both trap geometries with a fixed RF voltage amplitude of 150 V. The grey-shaded region indicates unstable trapping conditions where the ratio exceeds 0.2, violating the commonly accepted stability criterion for linear RF traps. (b) Radial secular frequency $\omega$ as a function of RF drive frequency for a $^{171}$Yb$^+$ ion under the same RF voltage. The dashed vertical line at 11 MHz indicates the selected operating point, which yields a radial trap frequency of 2.24 MHz in the 3D-printed trap. This point lies near the upper boundary of the stable region and is chosen to maximize confinement strength while ensuring trap stability.
• Figure 3: Schematic and spatial heating analysis of the conventional blade ion trap. (a) Schematic representation of the conventional blade trap used for trapped‑ion confinement. Blue electrodes correspond to RF potentials and yellow electrodes correspond to DC potentials. The ion is located at the geometric center of the quadrupole formed by four blade electrodes. The same 200 $\mu$m ion-to-electrode distance is used for both the skeleton trap and the blade trap to enable a controlled comparison of electric-field-induced heating between the two designs. (b) Spatial distribution of heating‑rate contributions to the radial motional mode from localized patch potentials on the electrode surfaces. Each color map illustrates the normalized contribution of individual surface patches to the total heating rate, highlighting dominant noise regions near the ion. Point A marks the location of the patch that gives the highest heating rate in the radial motional mode, corresponding to the region closest to the ion (200 $\mu$m). The red sphere represents the ion. (c) Spatial distribution of heating‑rate contributions to the axial motional mode. In contrast to the radial case, axial‑mode heating exhibits a non‑monotonic profile, with maximum contributions arising from patches located at intermediate distances (approximately 110 $\mu$m from the ion) indicated by points B and B'. The red sphere again denotes the ion position.
• Figure 4: Spatially resolved analysis of electric‑field‑induced heating in the 3D‑printed skeleton ion trap. (a) Heating‑rate contributions to the radial motional mode from surface patches on the skeleton electrodes. Point A marks the surface patch giving the highest radial‑mode heating rate, corresponding to the region closest to the ion (200 $\mu$m). The red sphere represents the ion. (b) Heating‑rate contributions to the axial motional mode. The red sphere again denotes the ion position. Each color map in (a) and (b) shows the relative contribution of individual surface patches to the total heating rate, where color intensity represents the normalized value as a fraction of the total. Points B and B' indicate the surface patches giving the highest axial‑mode heating rates. These results highlight the spatial dependence of motional heating in the 3D‑printed skeleton trap, revealing mode‑specific regions of dominant electric‑field noise. Compared to the blade trap, the 3D-printed skeleton trap exhibits a substantial suppression of heating contributions, especially near the ion, due to its hollow, minimal-surface-area electrode structure.
• Figure 5: Axial-mode heating behavior in linear ion traps analyzed through patch potential simulations. (a) Axial heating rate contributions from surface patch potentials along a single RF electrode. A distinct peak is observed at approximately 110 $\mu$m away from the ion position, illustrating that the dominant contribution to axial heating arises from patches not closest to the ion. (b) Linear relationship between the ion-to-electrode distance and the axial position of maximum heating rate. Each data point represents a different trap geometry. The observed linear trend confirms that the location of dominant axial-mode heating shifts proportionally with trap size. The fitted line follows the equation $y = 0.6x - 10$, where $x$ is the ion-to-electrode distance and $y$ is the distance from the ion to the peak axial heating source.