Detecting and Distinguishing Majorana Modes through Atomic Scale Shot Noise

Informazioni relative al progetto

DMShot

ID dell’accordo di sovvenzione: 101152827

DOI

10.3030/101152827

Progetto chiuso

Data della firma CE 12 Marzo 2024

Data di avvio 1 Aprile 2024

Data di completamento 31 Marzo 2026

Finanziato da

• Marie Skłodowska-Curie Actions (MSCA)

Costo totale

Nessun dato

Contributo UE

€ 211 754,88

Coordinato da

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
France

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

Periodo di rendicontazione: 2024-04-01 al 2026-03-31

Sintesi del contesto e degli obiettivi generali del progetto

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.

Lavoro eseguito dall’inizio del progetto fino alla fine del periodo coperto dalla relazione e principali risultati finora ottenuti

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.

Progressi oltre lo stato dell’arte e potenziale impatto previsto (incluso l’impatto socioeconomico e le implicazioni sociali più ampie del progetto fino ad ora)

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.