Quantum transport in EuTiO3 thin films
- Datum: 26.06.2018
- Uhrzeit: 16:00
- Vortragende(r): Prof. M. Kawasaki
- RIKEN Center for Emergent Matter Science (CMES), Wako, Saitama 351-0198, Japan Department of Applied Physics and Quantum-Phase Electronics Center, University of Tokyo, Bunkyo, Tokyo 113-8656, Japan
- Ort: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle (Saale)
- Raum: New Lecture Hall, Building B
EuTiO3 (ETO) is a magnetic semiconductor, in which 4f 7 moment on Eu2+ site orders in G-type antiferromagnet below 5.5 K and transforms into ferromagnet under a magnetic field above 3T. Electron carriers are doped in Ti t2g conduction band by the substitution of Eu2+ with La3+. We previously reported that a metalorganic gas source molecular beam epitaxy (MOMBE) at very high substrate temperature materializes the high electron mobility quantum well system of La-doped SrTiO3 (STO) that can host quantum Hall effect . We have extended the synthesis to compressively strained EuTiO3 films to observe novel Hall effect arising from magnetic monopole at the Wyle nodes created by crystal-field and Zeeman splittings of Ti 3d bands .
We now discuss the transport properties of 100nm thick Eu1-xLaxTiO3 films grown on lattice-matched STO substrates by the MOMBE. Despite there are two unfavorable conditions compared with STO case, magnetic moment on Eu site and absence of quantum paraelectricity, the electron mobility exceeds 3,000 cm2V-1s-1 at 2 K, Shubnikov–de Haas (SdH) oscillations being clearly observable in high magnetic field. This quantum transport provides opportunities to discuss the detailed band structures with taking into account the Zeeman splitting and exchange coupling between Eu 4f and Ti 3d electrons.