Programmable frequency-bin quantum states in a nano-engineered silicon device.

Area of Science:

• Quantum Information Science
• Nanophotonics
• Quantum Optics

Background:

• Photonic qubits require on-chip control and noise tolerance for practical quantum networks.
• Programmable, high-brightness qubit sources are essential for quantum algorithms and loss resilience.
• Existing encoding schemes often lack multiple key properties simultaneously.

Purpose of the Study:

• To demonstrate a silicon nano-photonic chip capable of generating frequency-bin entangled photons.
• To overcome limitations of existing encoding schemes by combining multiple essential qubit properties.
• To showcase on-chip programmability and compatibility with telecommunication infrastructure.

Main Methods:

• Development of a programmable silicon nano-photonic chip.
• Generation of frequency-bin entangled photons.
• Manipulation of quantum states using telecommunication components and integrated active devices.

Main Results:

• Demonstrated a programmable chip generating frequency-bin entangled photons.
• Showcased compatibility with long-range optical network transmission.
• Successfully programmed the chip to generate four computational basis states and four Bell states for a two-qubit system.
• Achieved high brightness, fidelity, and purity in the generated quantum states.

Conclusions:

• The developed silicon nano-photonic chip integrates on-chip reconfigurability, dense integration, high brightness, fidelity, and purity.
• This device overcomes previous limitations by combining multiple key properties for photonic qubits.
• Enables practical applications in quantum computing and communication networks.