7 papers · 1 filter
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…
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…
Dynamically generated concatenated codes and their phase diagrams
Grace M. Sommers, David A. Huse, Michael J. Gullans
We formulate code concatenation as the action of a unitary quantum circuit on an expanding tree geometry and find that for certain classes of gates, applied identically at each nod…
Roughening Transition in Quantum Circuits
Hyunsoo Ha, David A. Huse, Grace M. Sommers
We explore a roughening phase transition that occurs in the entanglement dynamics of certain quantum circuits. Viewing entanglement as the free energy of a membrane in a circuit-de…