학술논문

Nematic versus Kekul\'e phases in twisted bilayer graphene under hydrostatic pressure
Document Type
Working Paper
Source
Subject
Condensed Matter - Mesoscale and Nanoscale Physics
Language
Abstract
We address the precise determination of the phase diagram of magic angle twisted bilayer graphene under hydrostatic pressure within a self-consistent Hartree-Fock method in real space, including all the remote bands of the system. We further present a novel algorithm that maps the full real-space density matrix to a reduced density matrix based on a $SU(4)$ symmetry of sublattice and valley degrees of freedom. We find a quantum critical point between a nematic and a Kekul\'e phase, and show also that our microscopic approach displays a strong particle-hole asymmetry in the weak coupling regime. We arrive then at the prediction that the superconductivity should be Ising-like in the hole-doped nematic regime, with spin-valley locking, and spin-triplet in the electron-doped regime.
Comment: 27 pages, 28 figures