Correlation-Driven Insulator-Metal Transition in Near-Ideal Vanadium Dioxide Films.
Phys Rev Lett
; 116(11): 116403, 2016 Mar 18.
Article
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| MEDLINE
| ID: mdl-27035314
ABSTRACT
We use polarization- and temperature-dependent x-ray absorption spectroscopy, in combination with photoelectron microscopy, x-ray diffraction, and electronic transport measurements, to study the driving force behind the insulator-metal transition in VO_{2}. We show that both the collapse of the insulating gap and the concomitant change in crystal symmetry in homogeneously strained single-crystalline VO_{2} films are preceded by the purely electronic softening of Coulomb correlations within V-V singlet dimers. This process starts 7 K (±0.3 K) below the transition temperature, as conventionally defined by electronic transport and x-ray diffraction measurements, and sets the energy scale for driving the near-room-temperature insulator-metal transition in this technologically promising material.
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MEDLINE
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Revista:
Phys Rev Lett
Año:
2016
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Article
País de afiliación:
Estados Unidos