Tunable Generation of Spatial Entanglement in Nonlinear Waveguide Arrays

Area of Science:

• Quantum Optics and Photonics
• Quantum Information Science
• Integrated Photonics

Background:

• High-dimensional entangled states of light are crucial for quantum information technologies.
• The spatial degree of freedom is ideal for on-chip integration but traditionally requires discrete optical elements.
• Continuously coupled nonlinear waveguide systems offer a compact alternative for generating and manipulating entangled photons.

Purpose of the Study:

• To implement a compact and reconfigurable source of path-entangled photon pairs.
• To leverage continuously coupled nonlinear waveguide systems for on-chip quantum information processing.
• To engineer specific spatial correlations in entangled photon pairs.

Main Methods:

• Utilized parametric down-conversion in semiconductor nonlinear waveguide arrays.
• Employed a double-pump configuration to engineer the output quantum state.
• Exploited quantum interference between biphoton states generated in pumped waveguides.

Main Results:

• Demonstrated a compact and reconfigurable source of path-entangled photon pairs.
• Achieved engineered spatial correlations at room temperature and telecom wavelengths.
• Showcased the potential of continuously coupled waveguide systems for quantum applications.

Conclusions:

• Continuously coupled nonlinear waveguide systems provide a powerful platform for on-chip quantum information.
• This approach offers a promising alternative to discrete optical circuits for manipulating spatial entanglement.
• The developed source has significant implications for advancing quantum computation and communication.