Multi-Channel AOM Control for Trapped-Ion Quantum Gates

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Solution Overview

Problem

Existing quantum information processing systems using trapped ions face challenges in accurately controlling the states of individual ions due to systematic errors caused by residual operations from global optical beams, leading to phase shifts and energy shifts that accumulate over time, limiting the flexibility and accuracy of quantum operations.

Innovation Solution

Employing a multi-channel acousto-optic modulator (AOM) to independently control the phase, frequency, and amplitude of Raman beams for each trapped ion, allowing for individual correction of systematic errors through simultaneous control of multiple beams, thereby mitigating phase and energy shifts during quantum gate operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If global optical beams are used to control trapped ions, then quantum operations can be performed, but systematic errors accumulate due to residual operations causing phase and energy shifts

Engineering Contradiction:
Improvequantum operation capabilityVSAvoidstate control accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent divides the control approach by using individual addressing optical beams for each ion in addition to global beams. This segmentation allows independent control of each ion's state, enabling correction of systematic errors that affect individual ions differently, thus resolving the contradiction between operational capability and control accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs acousto-optic modulators to dynamically adjust parameters (frequency, phase, amplitude) of addressing optical beams. By changing these parameters, the system can compensate for accumulated phase and energy shifts in individual ions, maintaining state control accuracy while continuing quantum operations.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If individual addressing beams are added to control each ion, then systematic errors can be corrected, but device complexity increases

Engineering Contradiction:
Improvestate control accuracyVSAvoidoptical control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a single acousto-optic modulator to control multiple addressing optical beams simultaneously. This multi-functional approach allows one device to perform what would otherwise require multiple separate control systems, reducing overall device complexity while maintaining the ability to correct systematic errors for each ion.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The acousto-optic modulator serves as an intermediary device that translates control signals into precise adjustments of multiple optical beams. This intermediary component simplifies the control architecture by providing a centralized mechanism to manage the complexity of individual ion addressing without requiring separate control electronics for each beam.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system enables precise and flexible control of trapped ion states, reducing systematic errors and enhancing the accuracy and efficiency of quantum operations by dynamically correcting phase and energy shifts, ensuring stable quantum gate performance.

Implementation Method 1

multi-channel acousto-optic modulator (AOM) to independently control the phase, frequency, and amplitude of Raman beams

Methodology Applied
Scientific EffectAcousto-optic modulation: Acousto-optic Effect

Implementation Method 2

Raman transitions where the beatnote between two Raman beams (e.g., laser or optical beams) can coherently drive the internal qubit state

Methodology Applied
Scientific EffectRaman transition:

Implementation Method 3

the beatnote between two Raman beams (e.g., laser or optical beams) can coherently drive the internal qubit state

Methodology Applied
Scientific EffectBeatnote interference: Interference

Data Source

PatentEP3824415B1Multi-qubit control with acousto-optic modulators
Publication Date: 2025.09.17 IONQ INC
  • EP3824415B1 patent drawingFigure 1A
  • EP3824415B1 patent drawingFigure 1B~1C
  • EP3824415B1 patent drawingFigure 2A

AI summary

Aspects of the present disclosure describe techniques for controlling quantum states of ions in an ion chain for a quantum operation. For example, a method is described that includes providing, from a first direction, a global optical beam to the ions in the ion chain, and providing, from a second direction different from the first direction, to each ion in a subset of the ions in the ion chain, a respective addressing optical beam. The method further includes dynamically controlling each of the addressing optical beams being provided by using a respective channel in a multi-channel acousto-optic modulator (AOM) to implement, with the ion chain, one or more quantum gates in a sequence of quantum gates of the quantum operation. Aspects of a quantum information processing (QIP) system that includes the multi-channel AOM for performing the method are also described.