Thickness dependence of quantum oscillations in Weyl semimetal SrRuO3
Uddipta Kar1,5*, Chih-Yu Lin1,7, Yu-Te Hsu2,6, Bipul Das1, Cheng-Tung Cheng1, Akhilesh Kr. Singh1, Song Yang4, Chun-Yen Lin4, Chia-Hung Hsu4, S. Wiedmann2,6, Wei-Cheng Lee3, Wei-Li Lee1
1Physics, Academia Sinica, Taipei, Nangang, Taiwan
2High Field Magnet Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, Netherlands
3Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902, USA
4National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
5Nano Science and Technology, Taiwan International Graduate Program, Academia Sinica and National Taiwan university, Taipei, Nangang, Taiwan
6Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, Netherlands
7Physics, National Taiwan University, Taipei 10617, Taiwan
* Presenter:Uddipta Kar,
Using the adsorption-controlled growth technique with an oxide molecular beam epitaxy (MBE) system, we succeeded to grow high crystalline SrRuO3(SRO) films on SrTiO3(001)(STO) substrates, showing a residual resistivity at T =2.5 K (ρ(2.5 K)) of about  12.31 to 3.24 Ω cm as the SRO film thickness (t) varies from 7.7 to 35.3 nm. Rigorous magnetotransport measurements on SRO films with different ts were performed up to a field strength of about 35 T, where pronounced quantum oscillations with several distinct frequencies were observed. In particular, we uncovered an unusual frequency of about 30 T in the quantum oscillation, which behaves as a small two-dimensional Fermi pocket as confirmed from its angle dependence. The corresponding Landau fan diagram also showed a distinct feature that can be understood within the framework of Weyl-orbit effect, where the top and bottom Fermi-arc surface states collaborate with the bulk Weyl nodes to form a remarkable nonlocal cyclotron orbit. Detailed thickness dependence and angle dependence of the quantum oscillations in SRO films will be presented and discussed.

Keywords: Quantum oscillation, SrRuO3 thin film, Weyl semimetal