Extended linear-in-$T$ resistivity due to electron-phason scattering in moiré superlattices

Abstract

Due to its incommensurate nature, moiré superlattices host not only acoustic phonons but also another type of soft collective modes called phasons. Here, we investigate the impact of electron-phason scattering on the transport properties of moiré systems. We show that the resistivity can scale linearly with temperature down to temperatures much lower than the Bloch-Grüneisen scale defined by electron kinematics on the Fermi surface. This result stems from the friction between layers, which transfers phason spectral weight to a broad diffusive low-energy peak in the mechanical response of the system. As a result, phason scattering becomes a very efficient channel for entropy production at low temperatures. We also consider the contributions of phasons to thermodynamic properties at low temperatures and find a ''metallic-like'' linear-in-$T$ behavior for the specific heat, despite the fact that this behavior is due to mechanical and not electronic degrees of freedom. We discuss the implications of this finding to reports of linear-in-$T$ resistivity in the phase diagram of twisted bilayer graphene.

12 pages, 5 figures; new calculations of the resistivity and the specific heat added

References in corpus (8)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Acoustic phonon scattering limited carrier mobility in 2D extrinsic graphene
• Band structure and insulating states driven by the Coulomb interaction in twisted bilayer graphene
• Phonon-limited resistivity of graphene by first-principle calculations: electron-phonon interactions, strain-induced gauge field and Boltzmann equation
• Gauge phonon dominated resistivity in twisted bilayer graphene near magic angle
• Symmetry Origin of Lattice Vibration Modes in Twisted Multilayer Graphene: Phasons vs Moiré Phonons
• Moiré phonons and impact of electronic symmetry breaking in twisted trilayer graphene
• Glassy heat capacity from overdamped phasons and a hypothetical phason-induced superconductivity in incommensurate structures

Cited by in corpus (6)

• Measuring Phonon Dispersion and Electron-Phason Coupling in Twisted Bilayer Graphene with a Cryogenic Quantum Twisting Microscope
• Flat and tunable moire phonons in twisted transition-metal dichalcogenides
• Theory of phonon spectroscopy with the quantum twisting microscope
• A critical nematic phase with pseudogap-like behavior in twisted bilayers
• Temperature crossovers in the specific heat of amorphous magnets
• Charged moiré phonons in twisted bilayer graphene