Conductivity Dynamics of the Metal to Insulator Transition in EuNiO3/LANiO3 Superlattices
Abstract
In numerous transition metal oxides (TMO), competition between the charge, lattice, spin, and orbital degrees of freedom lead to emergent phenomena with the insulator-to-insulator transition (IMT) being one of the most enigmatic from fundamental and applied perspectives. Recently, considerable effort has focused on the growth of TMO heterostructures with atomic layer precision with a view towards controlling and even creating new emergent behavior including the IMT. Simultaneously, ultrafast optical spectroscopy (UOS) has become a powerful approach to interrogate emergence, probing how interactions and competition between operative degrees of freedom in TMOs determine macroscopic properties. In this STIR project an initial foray into non-equilibrium studies in nickelate superlattices was pursued to investigate IMT dynamics. Using time-resolved terahertz spectroscopy we measured the non-equilibrium recovery of the initial low temperature antiferromagnetic insulating phase following a picosecond quench to the high temperature paramagnetic metallic phase. Following photo-excitation, the recovery proceeds through nucleation and growth of the AFI phase at the expense of the PM phase following rapid cooling below the IMT transition temperature (~150K). These results highlight the importance of mesoscopic physics in correlated materials revealing new length and timescales that arise during the course of a phase transition.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 07, 2016
- Accession Number
- AD1008800
Entities
People
- Richard D. Averitt
Organizations
- University of California, San Diego