Cluster states, a type of highly entangled state, are essential resources for quantum information processing. Here we demonstrated the generation of a time-domain linear cluster state (t-LCS) using a superconducting quantum circuit consisting of only two transmon qubits. By recycling the physical qubits, the t-LCS equivalent up to four physical qubits was validated by quantum state tomography with fidelity of 59%. We further confirmed the true generation of t-LCS by examining the expectation value of an entanglement witness. Our demonstrated protocol of t-LCS generation allows efficient use of physical qubits which could lead to resource-efficient execution of quantum circuits on large scale.
@article{arxiv.2105.08609,
title = {Generating time-domain linear cluster state by recycling superconducting qubits},
author = {Shotaro Shirai and Yu Zhou and Keiichi Sakata and Hiroto Mukai and Jaw-Shen Tsai},
journal= {arXiv preprint arXiv:2105.08609},
year = {2023}
}