Hybrid Quantum-Classical Computing

Overview

Hybrid Quantum-Classical Computing (HQCC) is the dominant paradigm for realizing near-term quantum advantage: rather than waiting for standalone fault-tolerant quantum computers, HQCC pairs classical HPC nodes with quantum processing units (QPUs), assigning each stage of a computation to the hardware best suited for it. Classical infrastructure handles pre-processing (quantum circuit transpilation, resource prediction, workload scheduling, QUBO compilation) and post-processing (error mitigation on QPU outputs), while QPUs execute the quantum-advantage portions of the workload. This architecture enables practical quantum use today with current 100–250 qubit devices.

Dell's HQCC reference architecture flows from client device → Dell servers → Host Processor (FPGA-based digital-to-analog conversion) → QPU → HPC output post-processing, with an Accelerated vQPU Server layer for classical quantum emulation of workloads up to ~35 qubits. HQCC infrastructure closely mirrors AI GPU infrastructure in memory footprint and GPU compute requirements, enabling organizations to leverage existing AI infrastructure investments.

The three highest-value near-term HQCC use cases identified as of 2025 are: chemical modeling (quantum processors natively simulate atomic interactions without the expensive overhead of encoding quantum effects classically), financial portfolio optimization (even a 0.1% improvement at large-asset-base scale yields high ROI, and quantum noise is tolerable since exact optimality is not required), and electric battery design (materials science simulation accelerates iteration cycles from physical prototypes to compute-simulated designs by 100x or more).