title: Speed limit of the insulator-metal transition in magnetite.
abstract: As the oldest known magnetic material, magnetite (Fe3O4) has fascinated mankind for millennia. As the first oxide in which a relationship between electrical conductivity and fluctuating/localized electronic order was shown, magnetite represents a model system for understanding correlated oxides in general. Nevertheless, the exact mechanism of the insulator-metal, or Verwey, transition has long remained inaccessible. Recently, three-Fe-site lattice distortions called trimerons were identified as the characteristic building blocks of the low-temperature insulating electronically ordered phase. Here we investigate the Verwey transition with pump-probe X-ray diffraction and optical reflectivity techniques, and show how trimerons become mobile across the insulator-metal transition. We find this to be a two-step process. After an initial 300 fs destruction of individual trimerons, phase separation occurs on a 1.5±0.2 ps timescale to yield residual insulating and metallic regions. This work establishes the speed limit for switching in future oxide electronics.
authors.affiliation: 1] Stanford Institute for Energy and Materials Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA [2].
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authors.lastname: de Jong
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authors.initials: R
authors.lastname: Kukreja
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authors.lastname: Trabant
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authors.identifier: 0000000318032468
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authors.lastname: Chang
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authors.initials: T
authors.lastname: Kachel
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authors.lastname: Beye
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authors.forename: O
authors.initials: O
authors.lastname: Krupin
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authors.lastname: Doehler
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authors.lastname: Esposito
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authors.initials: WS
authors.lastname: Lee
authors.forename: Y D
authors.initials: YD
authors.lastname: Chuang
authors.forename: D H
authors.initials: DH
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authors.lastname: Trigo
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authors.lastname: Pathey
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authors.initials: MS
authors.lastname: Golden
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authors.forename: C
authors.initials: C
authors.lastname: Schüßler-Langeheine
authors.forename: H A
authors.initials: HA
authors.lastname: Dürr
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