High-Stability Cryogenic System for Quantum Computing With Compact Packaged Ion Traps

IEEE Transactions on Quantum Engineering

Colin Fitzgerald¹  Steffen Kross¹  Tom Noel¹  Robert Fulton Spivey²  Junki Kim²  Jungsang Kim²  Ismail Volkan Inlek²  Geert Vrijsen²  Stephen Crain²  Chao Fang²  Zhubing Jia³  Ke Sun³ 

[1] ColdQuanta, Inc., Boulder, CO, USA;Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA;Department of Physics, Duke University, Durham, NC, USA;

关键词: Optomechanical design;    quantum computing;    trapped ions;   

DOI  :  10.1109/TQE.2021.3125926

来源: DOAJ

【 摘 要 】

Cryogenic environments benefit ion trapping experiments by offering lower motional heating rates, collision energies, and an ultrahigh vacuum (UHV) environment for maintaining long ion chains for extended periods of time. Mechanical vibrations caused by compressors in closed-cycle cryostats can introduce relative motion between the ion and the wavefronts of lasers used to manipulate the ions. Here, we present a novel ion trapping system where a commercial low-vibration closed-cycle cryostat is used in a custom monolithic enclosure. We measure mechanical vibrations of the sample stage using an optical interferometer, and observe a root-mean-square relative displacement of 2.4 nm and a peak-to-peak displacement of 17 nm between free-space beams and the trapping location. We packaged a surface ion trap in a cryopackage assembly that enables easy handling while creating a UHV environment for the ions. The trap cryopackage contains activated carbon getter material for enhanced sorption pumping near the trapping location, and source material for ablation loading. Using $^{171}$Yb$^{+}$ as our ion, we estimate the operating pressure of the trap as a function of package temperature using phase transitions of zig-zag ion chains as a probe. We measured the radial mode heating rate of a single ion to be 13 quanta/s on average. The Ramsey coherence measurements yield 330-ms coherence time for counter-propagating Raman carrier transitions using a 355-nm mode-locked pulse laser, demonstrating the high optical stability.

【 授权许可】

Unknown