Validating Quantum-Classical Programming Models with Tensor Network Simulations

TL;DR

This paper introduces a tensor network-based quantum circuit simulator, TNQVM, capable of verifying hybrid quantum-classical algorithms on larger qubit systems, aiding validation and benchmarking on near-term quantum hardware.

Contribution

The paper presents TNQVM, a scalable, extensible tensor network simulator for hybrid quantum-classical programs, enabling larger qubit simulations and validation of quantum algorithms.

Findings

Successfully verified randomized quantum circuits.

Validated variational quantum eigensolver algorithm.

Demonstrated extensibility across different hardware backends.

Abstract

The exploration of hybrid quantum-classical algorithms and programming models on noisy near-term quantum hardware has begun. As hybrid programs scale towards classical intractability, validation and benchmarking are critical to understanding the utility of the hybrid computational model. In this paper, we demonstrate a newly developed quantum circuit simulator based on tensor network theory that enables intermediate-scale verification and validation of hybrid quantum-classical computing frameworks and programming models. We present our tensor-network quantum virtual machine (TNQVM) simulator which stores a multi-qubit wavefunction in a compressed (factorized) form as a matrix product state, thus enabling single-node simulations of larger qubit registers, as compared to brute-force state-vector simulators. Our simulator is designed to be extensible in both the tensor network form and the classical hardware used to run the simulation (multicore, GPU, distributed). The extensibility of the TNQVM simulator with respect to the simulation hardware type is achieved via a pluggable interface for different numerical backends (e.g., ITensor and ExaTENSOR numerical libraries). We demonstrate the utility of our TNQVM quantum circuit simulator through the verification of randomized quantum circuits and the variational quantum eigensolver algorithm, both expressed within the eXtreme-scale ACCelerator (XACC) programming model.