Toric-boson model: Toward a topological quantum memory at finite temperature

Understand

We discuss the existence of stable topological quantum memory at finite temperature.

• At stake here is the fundamental question of whether it is, in principle, possible to store quantum information for macroscopic times without the intervention from the external world, that is, without error correction.
• We study the toric code in two dimensions with an additional bosonic field that couples to the defects, in the presence of a generic environment at finite temperature: the toric-boson model.
• Although the coupling constants for the bare model are not finite in the thermodynamic limit, the model has a finite spectrum.