Oral: Spectroscopic evidence of electron interactions in rhombohedral trilayer graphene

Rhombohedral trilayer graphene (RTG), characterized by multiple internal degrees of freedom, exhibits a variety of isospin symmetry-broken states and superconducting phases¹. In this study, we demonstrate that stacking a monolayer graphene on top of a Bernal bilayer graphene with a small twist angle results in well-defined domains with ABC-stacking orders². We observe various gate-tunable, layer-polarized states across ABA, ABC and domain wall regions. Using scanning tunneling microscopy and spectroscopy, we map the phase diagram of the RTG and identify a sequence of symmetry-broken metallic states that emerge while filling the flat band, including inter-valley coherent and half-metal phases. These findings provide insights into the correlated spectroscopic characteristics of single-gated RTG device, establishing a benchmark for future studies on phase transitions in this system.

Reference

1. Zhou, H., Xie, T., Ghazaryan, A., Holder, T., Ehrets, J. R., Spanton, E. M., Taniguchi, T., Watanabe, K., Berg, E., Serbyn, M. & Young, A. F. Half- and quarter-metals in rhombohedral trilayer graphene. Nature 598, 429–433 (2021).

2. Kerelsky, A., Rubio-Verdú, C., Xian, L., Kennes, D. M., Halbertal, D., Finney, N., Song, L., Turkel, S., Wang, L., Watanabe, K., Taniguchi, T., Hone, J., Dean, C., Basov, D. N., Rubio, A. & Pasupathy, A. N. Moiréless correlations in ABCA graphene. P. Natl Acad. Sci. USA 118, e2017366118 (2021).