Interaction-enhanced electron-hole and valley asymmetries in the lowest Landau level ofABA-stacked trilayer graphene

Abstract

In a magnetic field graphene trilayers support a special multiplet of 12 zero(-energy)-mode Landau levels with a threefold degeneracy in Landau orbitals. A close look is made into such zero-mode levels in ABA-stacked trilayers, with the Coulomb interaction taken into account. It turns out that the zero-mode Landau levels of ABA trilayers are greatly afflicted with electron-hole and valley asymmetries, which come from general hopping parameters and which are enhanced by the Coulomb interaction and the associated vacuum effect, the orbital Lamb shift, that lifts the zeromode degeneracy. These asymmetries substantially affect the way the zero-mode levels evolve, with filling, via Coulomb interactions; and its consequences are discussed in the light of experiments.

High-resolution tunneling spectroscopy of ABA-stacked trilayer graphene

“…1(b). In the past few years, the ABA TLG has attracted much attention because that it is an ideal platform to explore broken-symmetry quantum Hall and many-body states [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Although many interesting broken-symmetry quantum Hall states and interaction-induced phenomena have been observed in transport measurements [1][2][3][4][5][6][7][8][9][10], they are never being probed in scanning tunneling microscopy (STM) studies because of the difficulties in microscopically identifying the stacking order of the TLG and the limited spectroscopic resolution.…”