A Feedback Control Method to Maintain the Amplitude of the RF Signal Applied to Ion Traps
Open Access
- 17 January 2021
- journal article
- research article
- Published by MDPI AG in Applied Sciences
- Vol. 11 (2), 837
- https://doi.org/10.3390/app11020837
Abstract
For high-fidelity quantum operations in ion traps, it is important to maintain the secular frequency of the trapped ions at a constant value. The radial secular frequency is proportional to the amplitude of the radio frequency (RF) signal applied to ion traps. Owing to the changes in the ambient temperature of a helical resonator and the minute vibration of the optical table, the amplitude can vary. Recently, a method for reducing the fluctuation in the RF signal amplitude, using a commercial universal proportional-plus-integral (PI) controller, has been introduced, which, in turn, reduces the secular frequency drift of the trapped ions. The method improves the capability to maintain the secular frequency at a constant value. However, the structure of the controller is fixed; thus, the control method cannot be changed to suit different experimental conditions, and the different feedback configuration cannot be implemented to increase the resolution. In this paper, we develop a field-programmable gate array (FPGA)-based feedback controller that allows the implementation of various automatic control methods and feedback configurations. In our experiments, the fluctuation in the amplitude of the RF signal was 1.806% using a commercial universal PI controller. The fluctuation was reduced to 0.099% using the developed FPGA-based PI controller, and to 0.102% using the developed FPGA-based lag compensator. By employing the developed FPGA control method, many other automating control methods can be applied to achieve a stable and high-performance control of the secular frequency.This publication has 22 references indexed in Scilit:
- Optimized fast gates for quantum computing with trapped ionsPhysical Review A, 2020
- Hybrid Microwave-Radiation Patterns for High-Fidelity Quantum Gates with Trapped IonsPhysical Review Applied, 2020
- Robust Entanglement Gates for Trapped-Ion QubitsPhysical Review Letters, 2018
- Noise analysis for high-fidelity quantum entangling gates in an anharmonic linear Paul trapPhysical Review A, 2018
- Fast shuttling of a particle under weak spring-constant noise of the moving trapPhysical Review A, 2018
- Trapped-Ion Quantum Logic with Global Radiation FieldsPhysical Review Letters, 2016
- High-Fidelity Quantum Logic Gates Using Trapped-Ion Hyperfine QubitsPhysical Review Letters, 2016
- Arbitrary-speed quantum gates within large ion crystals through minimum control of laser beamsEurophysics Letters, 2006
- Quantum information processing with trapped ionsPhilosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2003
- Dynamics of noise-induced heating in atom trapsPhysical Review A, 1998