We realize the Landau–Streater (LS) and Werner–Holevo (WH) quantum channels for qutrits on IBM quantum computers. These channels correspond to the interaction between a qutrit and its environment that results in the globally unitarily covariant qutrit transformation violating the multiplicativity of the maximal p-norm. Our realization of the LS and WH channels is based on embedding the qutrit states into states of two qubits and using the single-qubit and two-qubit CNOT gates to implement the specific interaction. We employ the standard quantum gates, hence the developed algorithm suits any quantum computer. We run our algorithm on a 5-qubit computer and a 20-qubit computer, as well as on a simulator. We quantify the quality of the implemented channels comparing their action on different input states with theoretical predictions. The overall efficiency is quantified by the fidelity between the theoretical and experimental Choi states implemented on the 20-qubit computer.

中文翻译：

---

Werner-Holevo和Landau-Streater量子通道在量子计算机上的实现

我们实现了IBM量子计算机上用于Qutrit的Landau-Streater（LS）和Werner-Holevo（WH）量子通道。这些通道对应于qutrit及其环境之间的相互作用，从而导致全局unit协变量qutrit变换违反了最大p的乘法性-规范。LS和WH通道的实现基于将qutrit状态嵌入两个qubit的状态，并使用单qubit和两个qubit CNOT门来实现特定的交互作用。我们采用标准的量子门，因此开发的算法适合任何量子计算机。我们在5量子位计算机和20量子位计算机以及模拟器上运行算法。我们通过比较它们在不同输入状态下的作用与理论预测来量化所实现通道的质量。通过在20量子位计算机上实现的理论和实验Choi状态之间的保真度来量化总体效率。