Unconventional two-dimensional quantum oscillations in three-dimensional thick SrRuO3 films

SrRuO3 is a prototypical transition metal oxide that hosts rich physical properties, including itinerant ferromagnetism, high conductivity, and intrinsic Hall effect originating in the Weyl points. Recently, high-quality SrRuO3 films with residual resistivity ratios of more than 50 have been reported to exhibit quantum oscillations at low temperatures in spite of their strong electron correlation. While the origin of the oscillations has been discussed in relation to Weyl orbits based on the Weyl semimetal band structure, so far experimentally reported results are consistent neither with each other nor with theoretically expected behavior, leaving the origin of the oscillations in SrRuO3 films still elusive. In this report, we have carefully evaluated the quantum oscillations observed in three-dimensional thick SrRuO3 films with a high residual resistivity ratio of RRR = 82. We reveal the coexistence of two oscillation components both derived from two-dimensional electronic states and with slightly different masses, suggesting the involvement of surface Fermi arc states formed between different Weyl point pairs.