Topologically Protected Quantum Logic Gates with Valley-Hall Photonic Crystals

Area of Science:

• Photonics
• Quantum Computing
• Topological Materials

Background:

• Topological photonics offer enhanced robustness for optical devices against defects and environmental changes.
• Quantum logic gates are essential for quantum information processing and practical quantum computing.
• A key challenge is creating topologically protected 2x2 beam splitters required for quantum logic gates.

Purpose of the Study:

• To experimentally realize a topologically protected contradirectional coupler.
• To demonstrate the application of this coupler in constructing robust quantum logic gates.
• To advance the development of practical optical quantum computations.

Main Methods:

• Experimental realization of a topologically protected contradirectional coupler on a silicon photonic platform.
• Utilizing the coupler to implement quantum logic gates, specifically control-NOT and Hadamard gates.
• Assessing the fidelity and defect tolerance of the implemented quantum gates.

Main Results:

• Successful experimental realization of a topologically protected contradirectional coupler.
• Demonstration of quantum logic gates (control-NOT and Hadamard) with high experimental fidelities.
• Exhibition of a degree of tolerance against specific types of defects in the implemented gates.

Conclusions:

• The developed topologically protected contradirectional coupler is suitable for realizing quantum logic gates.
• This work represents a significant step towards practical optical quantum computations and signal processing.
• The findings pave the way for more robust quantum devices and future quantum information technologies.