Information Critical Phases in Decohered Quantum Systems
Analysis
This paper introduces the concept of an 'information critical phase' in mixed quantum states, analogous to quantum critical phases. It investigates this phase in decohered Toric codes, demonstrating its existence and characterizing its properties. The work is significant because it extends the understanding of quantum memory phases and identifies a novel gapless phase that can still function as a fractional topological quantum memory.
Key Takeaways
- •Introduces the concept of an information critical phase in mixed quantum states.
- •Demonstrates the existence of this phase in decohered Toric codes.
- •Characterizes the information critical phase, including its connection to fractional logical information preservation.
- •Proposes an optimal decoding protocol for recovering information in this phase.
Reference
“The paper finds an information critical phase where the coherent information saturates to a fractional value, indicating that a finite fraction of logical information is still preserved.”