Error suppression in multicomponent cat codes with photon subtraction and teleamplification

Area of Science:

• Quantum Information Science
• Quantum Optics
• Quantum Error Correction

Background:

• Multiphoton states are vulnerable to decoherence from passive loss channels.
• Existing methods involve noiseless attenuation and amplification, but improvements are needed for practical applications.

Purpose of the Study:

• To propose and analyze a novel scheme for suppressing errors in quantum information under passive losses.
• To enhance the robustness of encoded qubits on cat states against environmental and detection losses.

Main Methods:

• Combined use of multiphoton subtraction on four-component cat codes and teleamplification.
• Utilizing the back-action of photon subtraction to modify encoded qubits by suppressing higher photon numbers.
• Implementing teleamplification followed by error correction for qubit recovery.

Main Results:

• Achieved a worst-case fidelity over 93.5% with the proposed scheme, and 82% with noisy teleamplification alone.
• Demonstrated a minimum success probability of approximately 3.42% under specific loss and efficiency parameters.
• The method effectively combats large passive losses, crucial for quantum communication and qubit storage.

Conclusions:

• The proposed scheme offers a promising standard for combating passive losses in quantum information tasks.
• This technique is particularly relevant for the noisy intermediate-scale quantum (NISQ) era, enhancing direct quantum communication and qubit storage.