ComEPT · Combining Electrons and Phonons in Twisted materials

The recent discovery of correlated insulating states and unconventional superconductivity in twisted bilayer graphene triggered an intense research effort to understand the properties of moiré materials. The ability to manipulate electronic properties through the twist angle between two two-dimensional materials has given rise to the new field of twistronics. Besides novel electronic properties, moiré materials also feature unconventional vibrational properties, such as novel phason modes. The ability to control vibrations by twisting gives rise to the new field of twistnonics.Despite much progress, many experimental observations in moiré materials are not yet well understood. For example, the microscopic origin of the “strange” metal phase with a resistivity which is linear in temperature and the nature of pairing glue that induces superconductivity are hotly debated. To answer these questions, I propose to combine the fields of twistronics and twistnonics and study the role of electron-phonon interactions in twisted bilayer materials. Specifically, I plan to+ develop a computational framework to study electron-phonon interactions in moiré materials. Because of the large unit cells of moiré materials, standard implementations of this approach cannot be used. To overcome this challenge, I will combine force-field approaches for phonons with tight-binding methods for electrons and develop a new parallelized computer code.+ understand electron transport experiments in different twisted bilayer materials, including twisted bilayer transition metal dichalcogenides and twisted bilayer graphene. + study the electron-phonon mediated superconductivity in twisted bilayer materials. The results of these calculations will enable a detailed understanding of the interactions between electrons and phonons in moiré materials and enable the control of exotic quantum phenomena with the twist angles.