Correlation-driven insulator-metal transition in near-ideal vanadium dioxide films
- SLAC National Accelerator Lab., Menlo Park, CA (United States); Temple Univ., Philadelphia, PA (United States)
- IBM Almaden Research Center, San Jose, CA (United States)
- SLAC National Accelerator Lab., Menlo Park, CA (United States); Univ. of Amsterdam, Amsterdam (The Netherlands)
- SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
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 VO2. We show that both the collapse of the insulating gap and the concomitant change in crystal symmetry in homogeneously strained single-crystalline VO2 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.
- Research Organization:
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-76SF00515; AC02-05CH11231
- OSTI ID:
- 1261081
- Alternate ID(s):
- OSTI ID: 1242439; OSTI ID: 1379238
- Report Number(s):
- SLAC-PUB-16591; PRLTAO; arXiv:1503.07892
- Journal Information:
- Physical Review Letters, Vol. 116, Issue 11; ISSN 0031-9007
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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