A classical method for strongly correlated fermions that combines a Clifford circuit with a matrix product state (MPS). The Clifford circuit absorbs the large but classically simulable stabilizer entanglement (efficient by the Gottesman-Knill theorem), leaving the MPS to represent only the residual non-stabilizerness entanglement entropy, which sharply raises accuracy at a fixed bond dimension. Fermions are handled by first applying the Jordan-Wigner transformation to map the fermion problem onto a spin chain. Benchmarked on the spinless t-V and spinful Hubbard models, the scheme markedly outperforms a bare MPS, with the biggest gains in the strongly interacting regime.
This paper generalizes Clifford-circuits Augmented Matrix Product States (CAMPS) to interacting fermion systems. In CAMPS, a Clifford circuit absorbs the large but classically tractable (stabilizer) …