Current-induced successive structural phase transitions beyond thermal equilibrium in single-crystal VO2

Abstract

Nonequilibrium systems driven by external energy sources host unexplored physics; yet phase transitions beyond thermal equilibrium remain elusive. Here, we demonstrate that electric current induces structural phase transitions in single-crystal VO2, a prototypical strongly correlated material. At room temperature, synchrotron X-ray diffraction shows that a current density of 6.5 A/cm2 disrupts V-V dimers, driving a monoclinic-to-tetragonal insulator-to-metal transition, independent of Joule heating. Increasing the current to 10 A/cm2 triggers a discontinuous isotropic lattice expansion, stabilizing a novel tetragonal structure that does not exist in thermal equilibrium. Optical microscopy and microscopic Raman spectroscopy reveal dynamic domain motion and metastable phases, reminiscent of dissipative structures. These findings establish direct pathways to access hidden phases and symmetry changes beyond thermal equilibrium, broadening the frontiers of nonequilibrium thermodynamics.

References in corpus (12)

• Nonequilibrium dynamical mean-field theory and its applications
• Dynamical singlets and correlation-assisted Peierls transition in VO2
• Local Temperature Redistribution and Structural Transition During Joule-Heating-Driven Conductance Switching in VO2
• Temperature dependence of Mott transition in VO_2 and programmable critical temperature sensor
• Evidence of a pressure-induced metallization process in monoclinic VO${}_2$
• Structural instability of the rutile compounds and its relevance to the metal-insulator transition of VO2
• Magnetic-field-induced insulator-metal transition in W-doped VO2 at 500 T
• Current-Induced Gap Suppression in the Mott Insulator Ca${}_2$RuO${}_4$
• Ultrafast X-ray imaging of the light-induced phase transition in VO2
• A Unique Crystal Structure of Ca${}_2$RuO${}_4$ in the Current Stabilized Semi-Metallic State
• Molecular orbital formation and metastable short-range ordered structure in VO${}_2$
• Metallic monoclinic phase in VO${}_2$ induced by electrochemical gating: in-situ Raman study