Efficient Learning of Quantum States Prepared With Few Non-Clifford Gates II: Single-Copy Measurements

arXiv:2308.07175v2 Announce Type: replace-cross
Abstract: Recent work has shown that $n$-qubit quantum states output by circuits with at most $t$ single-qubit non-Clifford gates can be learned to trace distance $\epsilon$ using $\mathsf{poly}(n,2^t,1/\epsilon)$ time and samples. All prior algorithms achieving this runtime use entangled measurements across two copies of the input state. In this work, we give a similarly efficient algorithm that learns the same class of states using only single-copy measurements.

abstract algorithms arxiv circuits copy cs.lg epsilon gates prior quant-ph quantum qubit samples type work