Hybrid entanglement carrying orbital angular momentum

Area of Science:

• Quantum Information Science
• Quantum Optics
• Quantum Communication

Background:

• Hybrid entanglement combines continuous-variable (CV) and discrete-variable (DV) quantum states, offering advantages over separate CV and DV protocols.
• Increasing the degrees of freedom in entangled states can enhance information capacity.
• Orbital angular momentum (OAM) is a promising degree of freedom for quantum communication and precision measurement.

Purpose of the Study:

• To experimentally prepare hybrid entanglement that incorporates orbital angular momentum (OAM).
• To investigate the potential of multi-degree-of-freedom entanglement for advanced quantum information processing.

Main Methods:

• Utilized a q-plate to convert the wavefront of optical cat states, introducing OAM.
• Generated hybrid entanglement between a polarization-encoded DV qubit and a cat-encoded CV qubit.
• Measured topological charges and reconstructed Wigner functions to verify entanglement.

Main Results:

• Successfully prepared hybrid entangled states carrying OAM with topological charges l = 0, +1, and +2.
• Confirmed the presence of entanglement in the output states via non-zero logarithmic negativities.
• Demonstrated the feasibility of incorporating OAM into hybrid entanglement.

Conclusions:

• The experimental preparation of hybrid entanglement carrying OAM is a significant advancement.
• This work expands the degrees of freedom available for hybrid entanglement, creating a novel quantum resource.
• The developed hybrid entangled states have potential applications in enhancing quantum communication capacity and measurement precision.