24–28 Jul 2023
MPI-FKF
Europe/Berlin timezone

Machine Learning Microscopic Form of Nematic Order in twisted double-bilayer graphene

24 Jul 2023, 16:45
2h 45m
2D5 (MPI-FKF)

2D5

MPI-FKF

Contributed Poster Poster Session

Speaker

Mr João Augusto Sobral da Silva (University of Innsbruck)

Description

Modern scanning probe techniques, like scanning tunneling microscopy (STM), provide access to a large amount of data encoding the underlying physics of quantum matter. In this work, we analyze how convolutional neural networks (CNN) can be employed to learn effective theoretical models from STM data on correlated moiré superlattices. These engineered systems are particularly well suited for this task as their enhanced lattice constant provides unprecedented access to intra-unit-cell physics and their tunability allows for high-dimensional data sets within a single sample. Using electronic nematic order in twisted double-bilayer graphene (TDBG) as an example, we show that including correlations between the local density of states (LDOS) at different energies allows CNNs not only to learn the microscopic nematic order parameter, but also to distinguish it from heterostrain. These results demonstrate that neural networks constitute a powerful methodology for investigating the microscopic details of correlated phenomena in moiré systems and beyond.

Primary authors

Mr João Augusto Sobral da Silva (University of Innsbruck) Mr Stefan Obernauer (University of Innsbruck) Mr Simon Eli Turkel (Columbia University) Prof. Abhay Pasupathy (Columbia University, Brookhaven National Laboratory) Mathias Scheurer (UIBK)

Presentation materials

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