High-fidelity heralded quantum squeezing gate based on entanglement

Area of Science:

• Quantum Information Science
• Quantum Optics
• Continuous-Variable Quantum Computation

Background:

• Squeezing operations are fundamental to Gaussian quantum information processing.
• Recent advancements include high-fidelity heralded squeezing gates using noiseless linear amplifiers.
• The fidelity of these gates is sensitive to the purity of the auxiliary squeezed states.

Purpose of the Study:

• To analyze the fidelity limitations of existing heralded squeezing schemes based on squeezing.
• To develop a novel heralded squeezing gate immune to input squeezing purity.
• To enable perfect squeezing gates for fault-tolerant continuous-variable quantum computation.

Main Methods:

• Analysis of a previously proposed heralded squeezing scheme based on squeezing.
• Development of a new heralded squeezing gate utilizing quantum teleportation.
• Theoretical evaluation of the new scheme's performance with varying input squeezing purities.

Main Results:

• The fidelity of the previous scheme is highly dependent on the purity of the auxiliary squeezed state.
• A 6 dB pure squeezed state yields higher fidelity than a 15 dB thermal squeezed state in the prior scheme.
• The new teleportation-based scheme is robust against input squeezing purity and achieves higher fidelity.

Conclusions:

• The proposed teleportation-based heralded squeezing gate overcomes the limitations of prior methods.
• This new gate can leverage current high-quality squeezed states (e.g., 15 dB) for perfect gate realization.
• The scheme shows promise for other Gaussian operations and non-classical state squeezing.