TY - JOUR AU - Emanuel Knill AU - James van C2 - Physical Review A DA - 2019-04-23 DO - https://doi.org/10.1103/PhysRevA.99.042331 LA - en M1 - 99 PB - Physical Review A PY - 2019 TI - Approximate exchange-only entangling gates for the three-spin-1/2 decoherence-free subsystem ER -