TY  - EJOUR
AU  - Huang, Ze-Min
AU  - Colmenarez, Luis
AU  - Müller, Markus
AU  - Diehl, Sebastian
TI  - Coherent information as a mixed-state topological order parameter of fermions
IS  - arXiv:2412.12279
M1  - FZJ-2025-01525
M1  - arXiv:2412.12279
PY  - 2025
N1  - 20 pages, 13+3 figures
AB  - Quantum error correction protects quantum information against decoherence provided the noise strength remains below a critical threshold. This threshold marks the critical point for the decoding phase transition. Here we connect this transition in the toric code to a topological phase transition in disordered Majorana fermions at high temperatures. A quantum memory in the error correctable phase is captured by the presence of a Majorana zero mode, trapped in vortex defects associated with twisted boundary conditions. These results are established by expressing the coherent information, which measures the amount of recoverable quantum information in a given noisy code, in terms of a mixed-state topological order parameter of fermions. Our work hints at a broader connection of the robustness of quantum information in stabilizer codes and mixed-state topological phase transitions in symmetry protected fermion matter.
LB  - PUB:(DE-HGF)25
UR  - https://juser.fz-juelich.de/record/1038540
ER  -