Generating time-domain linear cluster state by recycling superconducting qubits

Abstract

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 resourceefficient execution of quantum circuits on large scale.

Deterministic one-way logic gates on a cloud quantum computer

“…A series of theoretical and experimental protocols for generating cluster states of superconducting qubits have been presented in [19][20][21][52][53][54][55][56][57][58][59], as well as theoretical protocols [2,29] for one-way logic gates in superconducting processors. However, experimental demonstrations of one-way quantum computing in superconducting systems were lacking until very recently [60,61].…”

Deterministic one-way logic gates on a cloud quantum computer

“…Moreover, a large variety of protocols on a series of one-way logic gates have been proposed and implemented, including singlequbit, two-qubit, and multi-qubit logic gates, e.g., the Toffoli gate and the CARRY gate [2,[17][18][19][20][21][22][23][24]. Moreover, there have been a number of experiments generating cluster states, and constructing one-way quantum logic gates, performed in optical systems [12,13,22,[25][26][27][28][29][30][31], trapped ions [32], and nuclear magnetic resonance (NMR) systems [33], and very recently, superconducting circuits [34,35].…”

“…[14][15][16][45][46][47][48][49][50][51][52], as well as theoretical protocols [2,24] for one-way logic gates in superconducting processors. However, experimental demonstrations of one-way quantum computing in superconducting systems were lacking until very recently [34,35].…”