InAs-Al Hybrid Devices Passing the Topological Gap Protocol

• DOI: 10.48550/arxiv.2207.02472
• Publication Date: 2023-06-21
• Authors: Morteza Aghaee; Arun Akkala; Zulfi Alam; Rizwan Ali; Alejandro Alcaraz...; Mariusz Andrzejczuk; Andrey E. Antipov; Pavel Aseev; Mikhail Astafev; Bela Bauer; Jonathan Becker; Srini Boddapati; Frenk Boekhout; Jouri Bommer; Tom Bosma; Leo Bourdet; Samuel Boutin; Philippe Caroff; Lucas Casparis; Maja Cassidy; Sohail Chatoor; Anna Wulf Christe...; Noah Clay; William S. Cole; Fabiano Corsetti; Ajuan Cui; Paschalis Dalampiras; Anand Dokania; Gijs de Lange; Michiel de Moor; Juan Carlos Estra...; Saeed Fallahi; Zahra Heidarnia F...; John Gamble; Geoff Gardner; Deshan Govender; Flavio Griggio; Ruben Grigoryan; Sergei Gronin; Jan Gukelberger; Esben Bork Hansen; Sebastian Heedt; Jesús Herranz Zam...; Samantha Ho; Ulrik Laurens Hol...; Henrik Ingerslev; Linda Johansson; Jeffrey Jones; Ray Kallaher; Farhad Karimi; Torsten Karzig; Evelyn King; Maren Elisabeth K...; Christina Knapp; Dariusz Kocon; Jonne Koski; Pasi Kostamo; Peter Krogstrup; Mahesh Kumar; Tom Laeven; Thorvald Larsen; Kongyi Li; Tyler Lindemann; Julie Love; Roman Lutchyn; Morten Hannibal M...; Michael Manfra; Signe Markussen; Esteban Martinez; Robert McNeil; Elvedin Memisevic; Trevor Morgan; Andrew Mullally; Chetan Nayak; Jens Nielsen; William Hvidtfelt...; Bas Nijholt; Anne Nurmohamed; Eoin O'Farrell; Keita Otani; Sebastian Pauka; Karl Petersson; Luca Petit; Dmitry I. Pikulin; Frank Preiss; Marina Quintero-P...; Mohana Rajpalke; Katrine Rasmussen; Davydas Razmadze; Outi Reentila; David Reilly; Richard Rouse; Ivan Sadovskyy; Lauri Sainiemi; Sydney Schreppler; Vadim Sidorkin; Amrita Singh; Shilpi Singh; Sarat Sinha; Patrick Sohr; Tomaš Stankevič; Lieuwe Stek; Henri Suominen; Judith Suter; Vicky Svidenko; Sam Teicher; Mine Temuerhan; Nivetha Thiyagarajah; Raj Tholapi; Mason Thomas; Emily Toomey; Shivendra Upadhyay; Ivan Urban; Saulius Vaitiekėnas; Kevin Van Hoogdalem; David Van Woerkom; Dmitrii V. Viazmi...; Dominik Vogel; Steven Waddy; John Watson; Joseph Weston; Georg W. Winkler; Chung Kai Yang; Sean Yau; Daniel Yi; Emrah Yucelen; Alex Webster; Roland Zeisel; Ruichen Zhao
• Keywords: Condensed Matter - Mesoscale and Nanoscale Physics; 0103 physical sciences; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); FOS: Physical sciences; 01 natural sciences

We present measurements and simulations of semiconductor-superconductor heterostructure devices that are consistent with the observation of topological superconductivity and Majorana zero modes. The devices are fabricated from high-mobility two-dimensional electron gases in which quasi-one-dimensional wires are defined by electrostatic gates. These devices enable measurements of local and non-local transport properties and have been optimized via extensive simulations to ensure robustness against non-uniformity and disorder. Our main result is that several devices, fabricated according to the design's engineering specifications, have passed the topological gap protocol defined in Pikulin et al. [arXiv:2103.12217]. This protocol is a stringent test composed of a sequence of three-terminal local and non-local transport measurements performed while varying the magnetic field, semiconductor electron density, and junction transparencies. Passing the protocol indicates a high probability of detection of a topological phase hosting Majorana zero modes as determined by large-scale disorder simulations. Our experimental results are consistent with a quantum phase transition into a topological superconducting phase that extends over several hundred millitesla in magnetic field and several millivolts in gate voltage, corresponding to approximately one hundred micro-electron-volts in Zeeman energy and chemical potential in the semiconducting wire. These regions feature a closing and re-opening of the bulk gap, with simultaneous zero-bias conductance peaks at both ends of the devices that withstand changes in the junction transparencies. The extracted maximum topological gaps in our devices are 20-60 $μ$eV. This demonstration is a prerequisite for experiments involving fusion and braiding of Majorana zero modes.<br/>Final version<br/>