TensorQC: Towards Scalable Quantum Classical Hybrid Compute via Tensor Networks*

Quantum processing units (QPUs) have to satisfy highly demanding quantity and quality requirements on their qubits to produce accurate results for problems at useful scales. Furthermore, classical simulations of quantum circuits generally do not scale. Instead, quantum circuit cutting techniques cut and distribute a large quantum circuit into multiple smaller subcircuits feasible for less powerful QPUs. However, the classical post-processing incurred from the cutting introduces runtime and memory bottlenecks. This work presents Ten- sorQC, which addresses the bottlenecks via tensor network based post-processing that minimizes the classical overhead by orders of magnitudes over prior parallelization techniques. Our experiments reduce the quantum area requirement by at least 60% over the purely quantum platforms. We also demonstrated benchmarks up to 200 qubits on a single GPU, much beyond the reach of the purely classical platforms.