Quantum advantage of fully guided single-mode squeezing for quantum teleportation and sensing

Area of Science:

• Quantum optics and photonics.
• Development of quantum technologies.

Background:

• Squeezed light sources are crucial for advancing continuous-variable quantum information processing.
• Achieving high-quality squeezed light in the telecom C-band is essential for fiber-optic integration.

Purpose of the Study:

• To demonstrate an operational analysis of fully guided single-mode squeezing in the telecom C-band.
• To evaluate the entanglement potential and sensing performance of the squeezed light source under realistic purity constraints.
• To establish practical benchmarks for fiber-compatible squeezed-light sources.

Main Methods:

• Utilized a Zn-indiffused MgO-doped periodically-poled lithium niobate (MgO:ppLN) ridge waveguide for squeezed light generation.
• Measured quadrature variances to compute purity, entropy, and quantum Fisher information.
• Applied Duan's inseparability criterion to quantify entanglement and nonclassicality.

Main Results:

• Observed -1.81±0.05 dB squeezing at 1550 nm, equivalent to -4.11±0.05 dB generated squeezing after loss compensation.
• Demonstrated a ~11% quantum advantage in phase sensitivity estimation over coherent states via the quantum Cramer-Rao bound.
• Quantified entanglement potential and established nonclassicality of two-mode squeezed states.
• Computed a ~73.4% fidelity for continuous-variable quantum teleportation.

Conclusions:

• The developed MgO:ppLN waveguide is a practical source of single-mode squeezed light in the telecom C-band.
• The source exhibits significant entanglement potential and quantum advantage for sensing applications.
• This work sets benchmarks for fiber-compatible squeezed-light sources in quantum technologies.