We describe how classical supercomputing can aid unreliable quantum processors of intermediate size to solve large problem instances reliably. We advocate using a hybrid quantumclassical architecture where larger quantum circuits are broken into smaller subcircuits that are evaluated separately, either using a quantum processor or a quantum simulator running on a classical supercomputer. Circuit compilation techniques that determine which qubits are simulated classically will greatly impact the system performance as well as provide a tradeoff between circuit reliability and runtime. We describe how classical supercomputing can aid unreliable quantum processors of intermediate size to solve large problem instances reliably. Wemore »
Hybrid QuantumClassical Computing Architectures
—We describe how classical supercomputing can aid unreliable quantum processors of intermediate size to solve large problem instances reliably. We advocate using a hybrid quantumclassical architecture where larger quantum circuits are broken into
smaller subcircuits that are evaluated separately, either using a quantum processor or a quantum simulator running on a classical supercomputer. Circuit compilation techniques that determine which qubits are simulated classically will greatly impact the system
performance as well as provide a tradeoff between circuit reliability and runtime.
 Award ID(s):
 1734006
 Publication Date:
 NSFPAR ID:
 10092451
 Journal Name:
 Proceedings of the 3rd International Workshop on PostMoore's Era Supercomputing
 Sponsoring Org:
 National Science Foundation
More Like this


Quantum computing (QC) is a new paradigm offering the potential of exponential speedups over classical computing for certain computational problems. Each additional qubit doubles the size of the computational state space available to a QC algorithm. This exponential scaling underlies QC’s power, but today’s Noisy IntermediateScale Quantum (NISQ) devices face significant engineering challenges in scalability. The set of quantum circuits that can be reliably run on NISQ devices is limited by their noisy operations and low qubit counts. This paper introduces CutQC, a scalable hybrid computing approach that combines classical computers and quantum computers to enable evaluation of quantum circuitsmore »

Generative modeling is a flavor of machine learning with applications ranging from computer vision to chemical design. It is expected to be one of the techniques most suited to take advantage of the additional resources provided by nearterm quantum computers. Here, we implement a datadriven quantum circuit training algorithm on the canonical BarsandStripes dataset using a quantumclassical hybrid machine. The training proceeds by running parameterized circuits on a trapped ion quantum computer and feeding the results to a classical optimizer. We apply two separate strategies, Particle Swarm and Bayesian optimization to this task. We show that the convergence of themore »

We propose a set of Belltype nonlocal games that can be used to prove an unconditional quantum advantage in an objective and hardwareagnostic manner. In these games, the circuit depth needed to prepare a cyclic cluster state and measure a subset of its Pauli stabilizers on a quantum computer is compared to that of classical Boolean circuits with the same, nearestneighboring gate connectivity. Using a circuitbased trappedion quantum computer, we prepare and measure a sixqubit cyclic cluster state with an overall fidelity of 60.6% and 66.4%, before and after correcting for measurementreadout errors, respectively. Our experimental results indicate that whilemore »

Recently, Bravyi, Gosset, and Konig (Science, 2018) exhibited a search problem called the 2D Hidden Linear Function (2D HLF) problem that can be solved exactly by a constantdepth quantum circuit using bounded fanin gates (or QNC^0 circuits), but cannot be solved by any constantdepth classical circuit using bounded fanin AND, OR, and NOT gates (or NC^0 circuits). In other words, they exhibited a search problem in QNC^0 that is not in NC^0. We strengthen their result by proving that the 2D HLF problem is not contained in AC^0, the class of classical, polynomialsize, constantdepth circuits over the gate set ofmore »