Manipulating electronic structure and transport in correlated oxide heterostructures

MPSD Seminar

  • Datum: 07.01.2016
  • Uhrzeit: 11:00 - 12:00
  • Vortragende(r): Ankit Disa
  • Department of Applied Physics, Yale University, New Haven, CT, USA
  • Ort: CFEL (Bldg. 99)
  • Raum: Seminar Room III, EG.080
  • Gastgeber: Andrea Cavalleri
In complex transition metal oxides, strong correlations between electrons lead to entangled ground states with many fascinating emergent phenomena, including magnetism and high-temperature superconductivity. Moreover, the interplay between structural, charge, spin, and orbital degrees of freedom in these systems opens up the possibility of inducing and influencing exotic phase behavior using state-of-the-art atomic layering techniques. In this talk, I describe the engineering of electronic structure and transport properties of complex oxides through atomically-precise control of dimensionality and interfacial structure using molecular beam epitaxy. Specifically, I focus on two studies related to the rare-earth nickelates, an archetypal correlated system. The first investigation concerns the thickness-induced metal-insulator transition in LaNiO3, in which we use synchrotron-based x-ray diffraction and magnetotransport to reveal the structural origin of the crossover and demonstrate the realization of two-dimensional conduction in LaNiO3 by surface engineering. The second project focuses on our ability to manipulate the orbital configuration in rare-earth nickelates. A combination of first-principles theory and synchrotron-based x-ray techniques illustrates that unique three-component heterostructuring can be used to effectively change the nickelate orbital structure to emulate that of the high-temperature superconducting cuprates, and, in fact, can tune the orbital configuration between the bulk structures. Both approaches are based on simple physical mechanisms and represent routes to explore and enhance a wide variety of orbitally-dependent phenomena in correlated oxides including metal-insulator transitions, spin switching and superconductivity.
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