General-Purpose Quantum Circuit Simulator with Projected Entangled-Pair States and the Quantum Supremacy Frontier

TLDR

Recent advances in quantum hardware have brought quantum computing to the brink of quantum supremacy. The study aims to create a general‑purpose quantum algorithm simulator by applying projected entangled‑pair states to strongly interacting two‑dimensional systems. Using projected entangled‑pair states, the authors simulate quantum circuits with classical complexity governed by entanglement rather than qubit count, and they apply this approach to random circuits to quantify memory and time requirements. They successfully computed a single amplitude for a 7×7 qubit lattice of depth 42 on the Tianhe‑2 supercomputer.

Abstract

Recent advances on quantum computing hardware have pushed quantum computing to the verge of quantum supremacy. Here, we bring together many-body quantum physics and quantum computing by using a method for strongly interacting two-dimensional systems, the projected entangled-pair states, to realize an effective general-purpose simulator of quantum algorithms. The classical computing complexity of this simulator is directly related to the entanglement generation of the underlying quantum circuit rather than the number of qubits or gate operations. We apply our method to study random quantum circuits, which allows us to quantify precisely the memory usage and the time requirements of random quantum circuits. We demonstrate our method by computing one amplitude for a 7×7 lattice of qubits with depth (1+40+1) on the Tianhe-2 supercomputer.