Reducing circuit complexity in optical quantum computation using 3D architectures.

Area of Science:

• Integrated photonics
• Quantum computation
• Waveguide optics

Background:

• Integrated photonic circuits are key for large-scale quantum computation.
• Minimizing loss and maximizing visibility in waveguide circuits are critical challenges.
• Planar waveguide systems require complex SWAP operations for distant mode coupling, increasing loss.

Purpose of the Study:

• To propose and demonstrate a 3D photonic architecture to overcome limitations of planar waveguide systems.
• To reduce circuit complexity and depth by geometrically bypassing intermediate operations.
• To improve fidelity and efficiency in integrated photonic quantum circuits.

Main Methods:

• Experimental construction of 2D and 3D waveguide architectures using femtosecond laser direct-writing.
• Implementation of Hong-Ou-Mandel interference between the most distant optical modes.
• Comparison of performance between 2D planar and 3D architectures.

Main Results:

• The 3D architecture demonstrated significant improvement in fidelity and efficiency compared to the 2D counterpart.
• Geometrically bypassing intermediate operations effectively mitigated loss and scattering.
• Reduced optical depth for circuits with complex beamsplitter operations was achieved.

Conclusions:

• The proposed 3D integrated photonic architecture offers a viable solution for enhancing quantum computation.
• This approach significantly improves fidelity and efficiency by simplifying optical mode coupling.
• The 3D design provides a pathway to more scalable and robust quantum computing platforms.