近日，荷兰代尔夫特理工大学的Srijit Goswami及其研究团队取得一项新进展。经过不懈努力，他们实现了二维电子气体中的两位点基塔耶夫链。相关研究成果已于2024年6月12日在国际权威学术期刊《自然》上发表。

在这项工作中，研究人员通过超导体近似区域耦合两个量子点，实现了二维电子气体中的两位点基塔耶夫链。研究人员演示了通过磁场的平面内旋转和通过近似区域的静电门控对点间耦合的系统控制。这使研究人员能够将系统调整到参数空间中的最佳点，在那里可以在隧道光谱中观察到鲁棒相关的零偏电导峰。

为了研究局域MBSs之间的杂化程度，研究人员探测了能谱随磁场的演化，并估计了马约拉纳偏振，这是马约拉纳量子比特的一个重要度量。在可扩展和灵活的二维平台上实现基塔耶夫链，为需要操纵和读取多个MBSs的更先进实验提供了现实的途径。

据悉，人工基塔耶夫链可用于设计超导体半导体杂化体中的马约拉纳束缚态(MBSs)。

附：英文原文

Title: A two-site Kitaev chain in a two-dimensional electron gas

Author: ten Haaf, Sebastiaan L. D., Wang, Qingzhen, Bozkurt, A. Mert, Liu, Chun-Xiao, Kulesh, Ivan, Kim, Philip, Xiao, Di, Thomas, Candice, Manfra, Michael J., Dvir, Tom, Wimmer, Michael, Goswami, Srijit

Issue&Volume: 2024-06-12

Abstract: Artificial Kitaev chains can be used to engineer Majorana bound states (MBSs) in superconductor–semiconductor hybrids. In this work, we realize a two-site Kitaev chain in a two-dimensional electron gas by coupling two quantum dots through a region proximitized by a superconductor. We demonstrate systematic control over inter-dot couplings through in-plane rotations of the magnetic field and via electrostatic gating of the proximitized region. This allows us to tune the system to sweet spots in parameter space, where robust correlated zero-bias conductance peaks are observed in tunnelling spectroscopy. To study the extent of hybridization between localized MBSs, we probe the evolution of the energy spectrum with magnetic field and estimate the Majorana polarization, an important metric for Majorana-based qubits. The implementation of a Kitaev chain on a scalable and flexible two-dimensional platform provides a realistic path towards more advanced experiments that require manipulation and readout of multiple MBSs.

DOI: 10.1038/s41586-024-07434-9

Source: https://www.nature.com/articles/s41586-024-07434-9