Ancillary-Qubit Majority Voting for High-Fidelity Quantum Gates
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Solution Overview
Problem
Quantum computers face challenges in maintaining high fidelity during qubit operations and readout measurements due to errors and de-coherence, which affect the accuracy and reliability of quantum gate operations.
Innovation Solution
The implementation of digital quantum gates with adiabatic sweeps and jumps, coupled with high fidelity gate operations and ancillary qubits for error correction through majority voting, improves the fidelity of quantum operations, particularly for X gates, by entangling qubits and using low fidelity measurements to correct errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If quantum gate operations are performed with standard fidelity, then the quantum computer can operate with simpler procedures, but error rates increase and reliability decreases
Solution Approach 1:
The quantum gate operation is segmented into multiple discrete steps: preparing ancillary qubits in a specific state, performing controlled-NOT operations between the target qubit and ancillary qubits, and finally measuring the ancillary qubits. This segmentation allows each step to be optimized independently and enables error correction through the collective outcome of multiple measurements.
Solution Approach 2:
Ancillary qubits are introduced as intermediary elements that mediate between the target qubit and the measurement process. These ancillary qubits absorb potential errors during controlled-NOT operations and serve as carriers for error information, allowing the target qubit to maintain its quantum state while errors are detected and corrected through measurement of the ancillary qubits.
2Reliability
If the number of ancillary qubits is increased for majority voting, then error correction capability improves, but the number of qubits required increases
Solution Approach 1:
The system allows dynamic adjustment of the number of ancillary qubits based on the desired fidelity level and computational requirements. By changing this parameter, users can optimize between error correction capability and resource consumption, adapting the system to different operational conditions and error rates without requiring a fixed architecture.
3Reliability
If adiabatic sweeps and jumps are used in digital quantum gates, then gate operation fidelity improves, but the duration of gate operations increases
Solution Approach 1:
The digital quantum gate implementation uses periodic adiabatic sweeps and jumps to achieve high-fidelity operations. The adiabatic sweep slowly evolves the system through energy levels to maintain coherence, while periodic jumps rapidly transition between states when needed. This periodic combination of slow and fast operations achieves both high fidelity and reasonable gate duration.
Data Source
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AI summary
Systems and methods are provided for improving fidelity of a quantum operation on a quantum bit of interest. A controlled quantum gate operation, controlled by the quantum bit of interest, id performed on an ancillary quantum bit. An energy state of the ancillary quantum bit is measured to facilitate the improvement of the fidelity of the quantum operation.