Experimental study of multiple-shot unitary channels discrimination using the IBM Q computers

Area of Science:

• Quantum Information Theory
• Quantum Computing Hardware

Background:

• Quantum channel discrimination is a key task in quantum information theory.
• Previous studies focused on theoretical aspects, lacking experimental validation on real hardware.

Purpose of the Study:

• To experimentally investigate the discrimination of two unitary quantum channels in a multiple-shot scenario.
• To assess the impact of quantum circuit design on discrimination accuracy on noisy quantum hardware.

Main Methods:

• Performed experiments on the IBM Brisbane quantum computer.
• Implemented and tested various quantum circuit architectures for channel discrimination.
• Analyzed the relationship between circuit depth, entanglement, and discrimination probability.

Main Results:

• Deep quantum circuits and those with excessive entanglement reduce discrimination accuracy.
• Circuit architectures balancing entanglement and discrimination power show improved resilience to hardware noise.
• A threshold value for circuit depth was identified for optimal performance.

Conclusions:

• Theoretically suboptimal circuit designs can be superior on noisy quantum hardware.
• Minimizing entanglement overhead is crucial for robust quantum channel discrimination.
• Findings suggest a paradigm shift in designing quantum circuits for practical applications.