Novel quantum transport phenomena at oxide interfaces

Denis Maryenko

RIKEN Center for Emergent Matter Science

The two-dimensional electron system confined at the MgZnO/ZnO heterointerface has experienced rapid advances in sample quality in recent years [1, 2]. A large electron band mass (m=0.3m₀), a large Landé g-factor (g=2) and a small dielectric constant (e₀=8.5) position the 2DES in ZnO in the electron correlation regime which is in an experimental realization unprecedented so far. I will discuss the results of recent electrical transport experiments, which include the measurement of mass of composite fermions in the lowest Landau level and for the first time the observation of even-denominator fractional quantum Hall states n=3/2 and n=7/2 outside of the realm of III-V heterostructures [3, 4].

In the second part of the talk I will discuss the laser-assisted molecular beam epitaxy growth of novel LaTiO₃/KTaO₃ heterostructure. The electrical transport indicates a low-dimensional nature of the electron gas formed at the interface. Such a system is a promising candidate to utilize a large spin-orbital coupling for emergence of a new type of electromagnetic phenomena that can be used for future device applications.

References:

[1] A. Tsukazaki, S. Akasaka, K. Nakahara, Y. Ohno, H. Ohno, D. Maryenko, A. Ohtomo,
M. Kawasaki, Nature Materials 9, 889 (2010)

[2] J. Falson, D. Maryenko, Y. Kozuka, A. Tsukazaki, M. Kawasaki
Applied Physics Express 4, 091101 (2011)

[3] D. Maryenko, J. Falson, Y. Kozuka, A. Tsukazaki, M .Onoda, H. Aoki, M. Kawasaki
Phys. Rev. Lett. 108, 186803 (2012)

[4] J. Falson, D. Maryenko, B. Friess, D. Zhang, Y. Kozuka, A. Tsukazaki, J. H. Smet,
M. Kawasaki, submitted to Science (2013)