Quantum engineering of Landau levels using isotopes in graphene-like graphite

Landau levels are cornerstones of a wide range of quantum phenomena and applications. Understanding the impact of the gauge field, or pseudomagnetic field, on the electronic structure of two-dimensional materials is critical for manipulating Landau electrodynamics. Here, we present using graphite as a unique material testbed for realizing isotope-induced pseudomagnetic field. Using magneto-Raman spectroscopy, we show that pure ¹²C graphite and ¹³C-doped graphite both exhibit graphene-like Landau level transitions. Remarkably, we demonstrate that ¹³C-doping leads to splitting of the Landau level transitions, a signature of pseudomagnetic field on the scale of 0.2 T. Moreover, the split Landau level transitions selectively couple with the G band phonon in distinct energy ranges. Our results highlight isotope doping as a feasible material engineering method of creating pseudomagnetic field and tuning magneto-optical properties in two-dimensional quantum materials.