11 Apr 2025
13:00  - 14:00

Guest lecture / Talk

Why Microsoft Hasn’t Created a New State of Matter — or a Topological Qubit: What Microsoft’s experiments show — and what they don’t

Henry Legg (University of St. Andrews)

Abstract: I will discuss my recent comments on Microsoft Quantum’s work [1,2], as well as Chetan Nayak’s talk at this year’s March meeting. In particular, I will show that nonlocal measurements of hybrid semiconductor devices are a poor measure of the superconducting gap and that the so-called topological gap protocol used by Microsoft Quantum to tune-up their devices into a purportedly topological regime is flawed. I will also discuss several questionable research practices by the Microsoft group. I will conclude with a discussion of recent work [3,4] where we demonstrate some of the many complications with interpreting nonlocal conductance.

[1] HFL, arXiv:2502.19560 (2025)

[2] HFL, arXiv:2503.08944 (2025)

[3] J. Feng, HFL,…, Y. Ando, Nature Physics (2025)

[4] S. Steer, HFL (work in progress)


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