Quantum-Enhanced HPC Simulations with Error Mitigation

As we approach utility-scale quantum computations which cannot be verified classically, solutions for cancelling noise and errors and ensuring guaranteed accuracy are becoming increasingly important. In this talk, we present a novel method of measuring tensor-network observables with QESEM,  Qedma's Error Suppression and Error Mitigation solution supporting accurate and reliable error mitigation on large scale quantum circuits. We demonstrate the effectiveness of this method in circuit cutting, where tensor-network-based operator back-propagation is applied to one part of a quantum circuit, while the complementary portion is executed on a quantum processor. Using QESEM, we obtain an unbiased estimator of the backpropagated observable on the quantum-prepared state. In particular, we apply the method to the kicked-Ising model, by executing back propagation on Fugaku supercomputer, and using IBM's heron QPUs. We show that this approach significantly extends the depth of  quantum circuit that can be executed on the QPU.  This demonstrates an integration of HPCs with quantum computers which allows an efficient quantum-enhanced classical simulation, expanding the frontier of what even the most powerful classical HPCs can accomplish.