Angle-robust Two-Qubit Gates in a Linear Ion Crystal

Abstract

In trapped-ion quantum computers, two-qubit entangling gates are generated by applying spin-dependent force which uses phonons to mediate interaction between the internal states of the ions. To maintain high-fidelity two-qubit gates under fluctuating experimental parameters, robust pulse-design methods are applied to remove the residual spin-motion entanglement in the presence of motional mode frequency drifts. Here we propose an improved pulse-design method that also guarantees the robustness of the two-qubit rotation angle against uniform mode frequency drifts by combining pulses with opposite sensitivity of the angle to mode frequency drifts. We experimentally measure the performance of the designed gates and see an improvement on both gate fidelity and gate performance under uniform mode frequency offsets.

10 pages, 11 figures

References in corpus (9)

• High-fidelity preparation, gates, memory and readout of a trapped-ion quantum bit
• Manipulation and Detection of a Trapped Yb+ Ion Hyperfine Qubit
• Robust two-qubit gates in a linear ion crystal using a frequency-modulated driving force
• Ion trap quantum gates with amplitude-modulated laser beams
• Robust Ising Gates for Practical Quantum Computation
• Phase-modulated decoupling and error suppression in qubit-oscillator systems
• Crosstalk Suppression in Individually Addressed Two-Qubit Gates in a Trapped-Ion Quantum Computer
• Designing Filter Functions of Frequency-Modulated Pulses for High-Fidelity Two-Qubit Gates in Ion Chains
• Robust two-qubit trapped ions gates using spin-dependent squeezing

Cited by in corpus (3)

• Individually Addressed Entangling Gates in a Two-Dimensional Ion Crystal
• Correction Formulas for the Mølmer-Sørensen Gate Under Strong Driving
• Pulse optimization for high-precision motional-mode characterization in trapped-ion quantum computers