Candidate for a Passively Protected Quantum Memory in Two Dimensions

Area of Science:

• Quantum Information Science
• Condensed Matter Physics

Background:

• Quantum error correction is crucial for building fault-tolerant quantum computers.
• Existing passively protected quantum memories require high spatial dimensions (4D+) and are unstable at finite temperatures.

Purpose of the Study:

• To propose a novel model for a passively protected quantum memory in two dimensions.
• To explore a driven-dissipative environment for inherent error correction capabilities.

Main Methods:

• Introduced the photonic-Ising model, utilizing a square lattice of photonic "cat qubits."
• Employed Ising-like dissipators and a driven-dissipative photonic environment to address specific error types.
• Investigated the role of Z_{2}-symmetry-broken phases in error correction.

Main Results:

• The photonic-Ising model demonstrates passive correction against both bit-flip and phase-flip errors in 2D.
• The scheme leverages local dissipative terms for error mitigation.
• The model is inspired by distinct Z_{2}-symmetry-broken phases.

Conclusions:

• The photonic-Ising model offers a viable pathway to stable, passively protected quantum memory in lower dimensions.
• This approach provides a new strategy for quantum error correction using engineered environments.
• Potential experimental realizations of the photonic-Ising model are discussed.