9 papers
Stable valleys in the glassy landscape of a low-density parity-check (LDPC) code
Grace M. Sommers, David A. Huse
Classical low-density parity-check (cLDPC) codes defined on expander graphs are a fundamental ingredient in the construction of good quantum LDPC codes, a recent milestone in quant…
Spectral properties and coding transitions of Haar-random quantum codes
Grace M. Sommers, J. Alexander Jacoby, Zack Weinstein +2
A quantum error-correcting code with a nonzero error threshold undergoes a mixed-state phase transition when the error rate reaches that threshold. We explore this phase transition…
Scalable accuracy gains from postselection in quantum error correcting codes
Hongkun Chen, Daohong Xu, Grace M. Sommers +3
Decoding stabilizer codes such as the surface and toric codes involves evaluating free-energy differences in a disordered statistical mechanics model, in which the randomness comes…
Contracting Tensor Networks with Generalized Belief Propagation
Joseph Tindall, Grace M. Sommers, Hilbert Kappen
Recent years have seen a growing interest in the use of belief propagation - an algorithm originally introduced for performing statistical inference on graphical models - for appro…
Belief Propagation and Tensor Network Expansions for Many-Body Quantum Systems: Rigorous Results and Fundamental Limits
Siddhant Midha, Grace M. Sommers, Joseph Tindall +1
Belief propagation (BP) provides a scalable heuristic for contracting tensor networks on loopy graphs, but its success in quantum many-body settings has largely rested on empirical…
Observation of a Fault Tolerance Threshold with Concatenated Codes
Grace M. Sommers, Michael Foss-Feig, David Hayes +2
We introduce a fault-tolerant protocol for code concatenation of a generalized Shor code using a butterfly network architecture with high noise thresholds and low ancilla overhead…