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arXiv · 2001.08580

Magnetic-field-induced insulator-metal transition in W-doped VO2 at 500 T

Yasuhiro H. Matsuda·Daisuke Nakamura·Akihiko Ikeda·Shojiro Takeyama·Yuji Muraoka·Yuki Suga
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Abstract

Metal-insulator (MI) transitions in correlated electron systems have long been a central and controversial issue in material science. Vanadium dioxide (VO2) exhibits a first-order MI transition at 340 K. For more than half a century, it has been debated whether electronic correlation or the structural instability due to dimerised V ions is the more essential driving force behind this MI transition. Here, we show that an ultrahigh magnetic field of 500 T renders the insulator phase of tungsten (W)-doped VO2 metallic. The spin Zeeman effect on the d electrons of the V ions dissociates the dimers in the insulating phase, resulting in the delocalisation of electrons. Because the Mott-Hubbard gap essentially does not depend on the spin degree of freedom, the structural instability is likely to be the more essential driving force behind the MI transition.

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Yasuhiro H. Matsuda, Daisuke Nakamura, Akihiko Ikeda, Shojiro Takeyama, Yuji Muraoka, Yuki Suga. 2020-01-23. Magnetic-field-induced insulator-metal transition in W-doped VO2 at 500 T. https://doi.org/10.1038/s41467-020-17416-w

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