Pulse optimization for high-precision motional-mode characterization in trapped-ion quantum computers
arXiv:2307.15841 · doi:10.1088/2058-9565/ad3a98
Abstract
High-fidelity operation of quantum computers requires precise knowledge of the physical system through characterization. For motion-mediated entanglement generation in trapped ions, it is crucial to have precise knowledge of the motional-mode parameters such as the mode frequencies and the Lamb-Dicke parameters. Unfortunately, the state-of-the-art mode-characterization schemes do not easily render the mode parameters in a sufficiently scalable and accurate fashion, due to the unwanted excitation of adjacent modes in the frequency space when targeting a single mode, an effect known as the \textit{cross-mode coupling}. Here, we develop an alternative scheme that leverages the degrees of freedom in pulse design for the characterization experiment such that the effects of the cross-mode coupling is actively silenced. Further, we devise stabilization methods to accurately characterize the Lamb-Dicke parameters even when the mode frequencies are not precisely known due to experimental drifts or characterization inaccuracies. We extensively benchmark our scheme in simulations of a three-ion chain and discuss the parameter regimes in which the shaped pulses significantly outperform the traditional square pulses.
20 pages, 7 figures
References in corpus (20)
- Fast and robust two-qubit gates for scalable ion trap quantum computing
- Robust two-qubit gates in a linear ion crystal using a frequency-modulated driving force
- Ion trap quantum gates with amplitude-modulated laser beams
- High-fidelity Two-qubit Gates Using a MEMS-based Beam Steering System for Individual Qubit Addressing
- Phase-modulated decoupling and error suppression in qubit-oscillator systems
- Demonstration of two-atom entanglement with ultrafast optical pulses
- Efficient ground-state cooling of large trapped-ion chains with an EIT tripod scheme
- Demonstration of three- and four-body interactions between trapped-ion spins
- Efficient, stabilized two-qubit gates on a trapped-ion quantum computer
- The Character of Motional Modes for Entanglement and Sympathetic Cooling of Mixed-Species Trapped Ion Chains
- Batch Optimization of Frequency-Modulated Pulses for Robust Two-qubit Gates in Ion Chains
- Designing Filter Functions of Frequency-Modulated Pulses for High-Fidelity Two-Qubit Gates in Ion Chains
- Numeric optimization for configurable, parallel, error-robust entangling gates in large ion registers
- Efficient sideband cooling protocol for long trapped-ion chains
- Constant-cost implementations of Clifford operations and multiply controlled gates using global interactions
- Efficient quantum programming using EASE gates on a trapped-ion quantum computer
- Coherence properties of highly-excited motional states of a trapped ion
- Angle-robust Two-Qubit Gates in a Linear Ion Crystal
- Efficient motional-mode characterization for high-fidelity trapped-ion quantum computing
- Optimised Bayesian system identification in quantum devices