Detecting and Distinguishing Majorana Modes through Atomic Scale Shot Noise

Project Information

DMShot

Grant agreement ID: 101152827

DOI

10.3030/101152827

Project closed

EC signature date 12 March 2024

Start date 1 April 2024

End date 31 March 2026

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 211 754,88

Coordinated by

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
France

Periodic Reporting for period 1 - DMShot (Detecting and Distinguishing Majorana Modes through Atomic Scale Shot Noise)

Reporting period: 2024-04-01 to 2026-03-31

Summary of the context and overall objectives of the project

The search for non-abelian states of matter has become a central theme of modern quantum material research. The ability to identify and control such states is essential for developing fault-tolerant quantum computers. Notably, Majorana zero modes are of special interest, as they can serve as the foundation for topological qubits. A robust zero-bias conductance peak, observed in scanning tunneling spectra, is often regarded as the primary signature of a Majorana zero mode. Yet similar features can also arise from trivial bound states, raising a long-standing challenge of how to distinguish genuine Majoranas from imposters. During the course of the project, we have successfully addressed this problem with a new approach, atomic-scale shot-noise spectroscopy, that goes beyond conductance measurements.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

WP1: Through a systematic study of defect-induced zero-energy states, I demonstrated that while conductance measurements alone may suggest robust Majorana-like signatures, shot-noise spectroscopy reveals their true trivial nature by resolving the underlying particle–hole asymmetry in tunneling processes. This establishes noise spectroscopy as a decisive tool for discriminating genuine Majorana modes from impostors.

WP2: Moving forward, using this approach, I investigated vortex-bound states in Fe(Se,Te), where Majorana bound states (MBS) have been proposed to exist. By comparing current noise in conventional Caroli–de Gennes–Matricon (CdGM) states and zero-energy vortex bound states (ZVBS), I demonstrated clear differences in tunneling dynamics. While CdGM states exhibit both incoherent single-electron tunneling and coherent Andreev processes, the ZVBS shows a near-unity Fano factor consistent with Majorana-assisted transport. Furthermore, by combining experimental data with theoretical modeling, I established a quantitative framework to extract intrinsic lifetimes, providing a pathway toward unambiguous identification of MBS in future low-temperature experiments.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Overall, this work represents a significant advance in experimental methodology and conceptual understanding, positioning atomic-scale shot-noise spectroscopy as a versatile and reliable probe for investigating correlated and topological quantum phenomena.