Ultrafast transient generation of spin-density-wave order in the normal state of BaFe2As2 driven by coherent lattice vibrations.

  title={Ultrafast transient generation of spin-density-wave order in the normal state of BaFe2As2 driven by coherent lattice vibrations.},
  author={K. W. Kim and Alexej Pashkin and Hanjo Schäfer and Markus Beyer and Michael Porer and Th. Wolf and Christian Bernhard and Jure Dem{\vs}ar and Rupert Huber and Alfred Leitenstorfer},
  journal={Nature materials},
  volume={11 6},
The interplay among charge, spin and lattice degrees of freedom in solids gives rise to intriguing macroscopic quantum phenomena such as colossal magnetoresistance, multiferroicity and high-temperature superconductivity. Strong coupling or competition between various orders in these systems presents the key to manipulate their functional properties by means of external perturbations such as electric and magnetic fields or pressure. Ultrashort and intense optical pulses have emerged as an… 
Ultrafast terahertz spin dynamics: from phonon-induced spin order to coherent magnon control
Ultrashort pulses in the terahertz (THz) spectral range allow us to study and control spin dynamics on time scales faster than a single oscillation cycle of light. In a first set of experiments, we
Non-thermal separation of electronic and structural orders in a persisting charge density wave.
It is shown that ultrabroadband terahertz pulses can simultaneously trace the ultrafast evolution of coexisting lattice and electronic orders and demonstrates the sort of profound insight that disentangling strongly coupled components of order parameters in the time domain may provide for the understanding of a broad class of phase transitions.
Transient Spin Density Wave Order Induced in the Normal State of BaFe2As2 by Coherent Lattice Oscillations
We trace the ultrafast dynamics of the spin density wave gap of the pnictide system BaFe2 As2 probing resonantly with broadband multi-terahertz pulses. The photoexcitation in the low-temperature
Ultrafast switching to an insulating-like metastable state by amplitudon excitation of a charge density wave
In correlated electron materials, multiple electronic phases may appear next to each other in their phase diagram, and these can be tuned, for example, by applying static pressure or chemical
Femtosecond low-energy dynamics of a charge density wave in TiSe2
  • M. Porer, J. Ménard, +5 authors R. Huber
  • Physics
    2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC
  • 2013
Summary form only given. The ultrafast interplay between charge and lattice in correlated electron systems often leads to spontaneous collective order. The charge density wave (CDW) in
Femtosecond control of phonon dynamics near a magnetic order critical point
This work combines double photoexcitation with an X-ray free-electron laser (XFEL) probe to control and detect the lifetime and magnitude of the intermediate vibrational state near the critical point of the SDW in chromium.
Dynamics of charge density wave order in the quasi one dimensional conductor (TaSe4)2I probed by femtosecond optical spectroscopy
Carrier and collective mode dynamics in the quasi one-dimensional charge density wave (CDW) system (TaSe4)2I have been investigated by means of time-resolved optical pump-probe spectroscopy. In the
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A model incorporating the time-dependent Ginzburg–Landau theory of ultrafast cooperative interplay among charge, spin, and lattice is presented for the pnictide superconductor BaFeAs. Under the


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The transient response of Ba(Fe1−xCox)2As2, x=0.08 was studied by pump-probe optical reflectivity. After ultrafast photoexcitation, hot electrons were found to relax with two different characteristic
Snapshots of cooperative atomic motions in the optical suppression of charge density waves
Effectively, the atomic motions that result from the optically induced change in the electronic spatial distribution are directly observed and the degree of cooperativity in the observed structural dynamics is remarkable and illustrates the importance of obtaining atomic-level perspectives of the processes directing the physics of strongly correlated systems.
Electron-phonon coupling and the charge gap of spin-density wave iron-pnictide materials from quasiparticle relaxation dynamics
We investigate the quasiparticle relaxation and low-energy electronic structure in undoped SrFe_2As_2 exhibiting spin-density wave (SDW) ordering using optical pump-probe femtosecond spectroscopy. A
Origin of the spin density wave instability in AFe2As2 (A=Ba,Sr) as revealed by optical spectroscopy.
It is elaborate that the spin-density-wave instability is more likely to be driven by the Fermi surface nesting of itinerant electrons than a local-exchange mechanism.
Symmetry-breaking orbital anisotropy observed for detwinned Ba(Fe1-xCox)2As2 above the spin density wave transition
Nematicity, defined as broken rotational symmetry, has recently been observed in competing phases proximate to the superconducting phase in the cuprate high-temperature superconductors. Similarly,
The dynamics of spin-density waves
Spin-density waves (SDWs) are broken-symmetry ground states of metals, the name referring to the periodic modulation of the spin density with period, [lambda][sub 0]=[pi]/[ital k][sub [ital F]],
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It is reported that bulk magnetism and superconductivity coexist and compete on the nanometer length scale and the bulk nature of SC is established by the μSR data which show a bulk SC vortex lattice and the IR data which reveal that the majority of low-energy states is gapped and participates in the condensate at T≪T(c).
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Coherent spin dynamics in the THz domain coupled to a coherent phonon is observed in the time-resolved second harmonic response of the Gd(0001) ferromagnetic metal surface. An LO phonon of 2.9 THz is