title: A charge density wave-like instability in a doped spin-orbit-assisted weak Mott insulator.
abstract: Layered perovskite iridates realize a rare class of Mott insulators that are predicted to be strongly spin-orbit coupled analogues of the parent state of cuprate high-temperature superconductors. Recent discoveries of pseudogap, magnetic multipolar ordered and possible d-wave superconducting phases in doped Sr2IrO4have reinforced this analogy among the single layer variants. However, unlike the bilayer cuprates, no electronic instabilities have been reported in the doped bilayer iridate Sr3Ir2O7. Here we show that Sr3Ir2O7realizes a weak Mott state with no cuprate analogue by using ultrafast time-resolved optical reflectivity to uncover an intimate connection between its insulating gap and antiferromagnetism. However, we detect a subtle charge density wave-like Fermi surface instability in metallic electron doped Sr3Ir2O7at temperatures (TDW) close to 200 K via the coherent oscillations of its collective modes, which is reminiscent of that observed in cuprates. The absence of any signatures of a new spatial periodicity below TDWfrom diffraction, scanning tunnelling and photoemission based probes suggests an unconventional and possibly short-ranged nature of this density wave order.
authors.affiliation: Department of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA.|Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: H
authors.initials: H
authors.lastname: Chu
authors.affiliation: Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA.|Department of Physics, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: L
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA.|Department of Physics, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: A
authors.initials: A
authors.lastname: de la Torre
authors.affiliation: Materials Department, University of California, Santa Barbara, California 93106, USA.
authors.forename: T
authors.initials: T
authors.lastname: Hogan
authors.affiliation: Materials Department, University of California, Santa Barbara, California 93106, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Wilson
authors.affiliation: Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125, USA.|Department of Physics, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: D
authors.initials: D
authors.lastname: Hsieh