Dirac cone spectroscopy of strongly correlated phases in twisted trilayer graphene

Abstract

Mirror-symmetric magic-angle twisted trilayer graphene (MATTG) hosts flat electronic bands close to zero energy, and has been recently shown to exhibit abundant correlated quantum phases with flexible electrical tunability.1–3 However studying these phases proved challenging as these are obscured by intertwined Dirac bands. In this work, we demonstrate a novel spectroscopy technique, that allows to quantify the energy gaps and Chern numbers of the correlated states in MATTG by driving band crossings between Dirac cone Landau levels and the energy gaps in the flat bands. We uncover hard correlated gaps with Chern numbers of C = 0 at integer moiré unit cell fillings of ν = 2 and 3 and reveal novel charge density wave states originating from van Hove singularities at fractional fillings of ν = 5/3 and 11/3. In addition, we demonstrate the existence of displacement field driven first-order phase transitions at charge neutrality and half fillings of the moiré unit cell ν = ± 2, which is consistent with a theoretical strong-coupling analysis, implying the breaking of the C2T symmetry. Overall these properties establish the diverse and electrically tunable phase diagram of MATTG and provide an avenue for investigating electronic quantum phases and strong correlations in multiple-band moiré systems.

A Study on the Utilization Plan for Functionally Lost Reservoirs: Focused on Daegu and Gyeongbuk

“…Our observations suggest a unique edge reconstruction involving both electrons and chiral pwave composite fermions.Recent advances in twistronics [1] have enabled the exploration of an extremely diverse set of quantum phases. They include unconventional superconducting ground states, correlated insulating phases as well as integer and fractional Chern insulating states [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. These phases form due to strong correlations in a flat band environment that possesses non-trivial topological characteristics and offers a pool of nearly degenerate electronic states.…”