Variational quantum simulation of the critical Ising model with symmetry averaging

Here, we investigate the use of deep multi-scale entanglement renormalization (DMERA) circuits as a variational ansatz for ground states gapless systems. We exactly-solvable one-dimensional critical transverse-field Ising model testbed. Numerically exact simulation can in this case be carried out to hundreds qubits by exploiting efficient classical algorithms simulating matchgate circuits. find that, system, DMERA strongly outperforms standard QAOA-style ansatz, and that major source systematic error correlation functions approximated using is breaking translational Kramers-Wannier symmetries model. are able reduce up four orders magnitude symmetry averaging, without incurring additional cost or circuit depth. propose technique mitigating could applied NISQ simulations physical systems with other symmetries.