Magnetic-field-induced insulator-metal transition in W-doped VO2 at 500 T.
Nat Commun
; 11(1): 3591, 2020 Jul 17.
Article
em En
| MEDLINE
| ID: mdl-32681051
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 electron 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. As 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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MEDLINE
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En
Ano de publicação:
2020
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Article