New quantum phase in a ZnO interface of best semiconductor quality New stream for topological quantum computer research

March 24, 2015

© 2015 Mari Ishida

© 2015 Mari Ishida

Heterointerfaces composed of dissimilar materials have been applied to functional devices such as transistors and light emitting diodes. In particular, the best-quality electron system is formed in gallium arsenide heterostructures, where a unique quantum phase was found at low temperature about 30 years ago. This quantum phase is expected to be applied for a new type of topological quantum computer which possesses dramatically improved computing speed while maintaining tolerance for computational error. However, the characteristics of this quantum phase have yet to be clarified.

Researchers at the Quantum Phase Electronics Center/Department of Applied Physics, the Graduate School of Engineering at the University of Tokyo, headed by Professor Masashi Kawasaki, in collaboration with a group headed by Dr. Jurgen Smet at the Max-Planck Institute, have fabricated ZnO heterostructures of unprecedented high quality, and observed the quantum phase in a material other than a GaAs heterostructure for the first time. This study has revealed that ZnO possesses a controllability that is absent in GaAs, indicating the significance of ZnO in order to improve our understanding of this quantum phase.

This research has been published in the online edition of Nature Physics (March 23, 2015). This research was performed in collaboration with PhD candidate Joseph Falson at the Graduate School of Frontier Sciences at the University of Tokyo, postdoctoral researcher Denis Maryenko at RIKEN CEMS, lecturer Yusuke Kozuka at the Department of Applied Physics, the Graduate School of Engineering at the University of Tokyo, and Professor Atsushi Tsukazaki at the Institute for Materials Research at Tohoku University.

Press release [PDF] (Japanese)


J. Falson, D. Maryenko, B. Friess, D. Zhang, Y. Kozuka, A. Tsukazaki, J. H. Smet, M. Kawasaki, "Even-denominator fractional quantum Hall physics in ZnO", Nature Physics Online Edition: 2015/3/23 (Japan time), doi: 10.1038/nphys3259.
Article link (Publication)


Graduate School of Engineering

Quantum-Phase Electronics Center, Graduate School of Engineering

Kawasaki Laboratory, Quantum-Phase Electronics Center, Graduate School of Engineering

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