Distinguishing a Majorana zero mode using spin-resolved measurements

• Published in: Science (American Association for the Advancement of Science) Vol. 358; no. 6364; pp. 772 - 776
• Main Authors: Jeon, Sangjun, Xie, Yonglong, Li, Jian, Wang, Zhijun, Bernevig, B. Andrei, Yazdani, Ali
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 10.11.2017; The American Association for the Advancement of Science; American Association for the Advancement of Science (AAAS)
• Subjects: Band structure of solids; Chains; Computation; Diagnostic software; Diagnostic systems; Hilbert space; Iron; Lead; Magnetism; Polarization; Quantum computing; Quantum theory; Scanning tunneling microscopy; Self-assembly; Spectroscopy; Superconductivity; Topological superconductors
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.aan3670

One-dimensional topological superconductors host Majorana zero modes (MZMs), the nonlocal property of which could be exploited for quantum computing applications. We use spin-polarized scanning tunneling microscopy to show that MZMs realized in self-assembled Fe chains on the surface of Pb have a spin polarization that exceeds that stemming from the magnetism of these chains. This feature, captured by our model calculations, is a direct consequence of the nonlocality of the Hilbert space of MZMs emerging from a topological band structure. Our study establishes spin-polarization measurements as a diagnostic tool to distinguish topological MZMs from trivial in-gap states of a superconductor.