Robust and Resource-Efficient Microwave Near-Field Entangling ^{9}Be^{+} Gate

Area of Science:

• Quantum information science
• Atomic physics
• Quantum computing

Background:

• Microwave trapped-ion quantum logic gates offer an alternative to laser-based approaches, circumventing spontaneous emission as a decoherence source.
• Despite advantages, microwave gates are slower than laser gates, increasing sensitivity to motional mode frequency fluctuations.

Purpose of the Study:

• To develop and implement amplitude-shaped gate drives for microwave trapped-ion quantum logic gates.
• To enhance the resilience of two-qubit gates to motional mode frequency fluctuations without increasing pulse energy.

Main Methods:

• Proposal and implementation of amplitude-shaped microwave pulse sequences for quantum logic gates.
• Utilizing beryllium ion ({}^{9}Be^{+}) qubits for experimental demonstration.
• Injecting noise during two-qubit entangling gate operations to test resilience.

Main Results:

• Amplitude-shaped gate drives demonstrate resilience to motional frequency noise.
• Operation infidelity in the 10^{-3} range was achieved in the absence of injected noise.
• The proposed method enhances gate performance under realistic noise conditions.

Conclusions:

• Amplitude shaping is an effective strategy to improve the robustness of microwave trapped-ion quantum gates.
• This technique offers a pathway to faster and more reliable quantum operations in trapped-ion systems.
• The findings contribute to the advancement of scalable and fault-tolerant quantum computing architectures.