Electronic Raman scattering from 3d8inter-term magnetic excitons in the planar antiferromagnet K2NiF4

Abdalian, A. T.; Moch, P.

doi:10.1088/0022-3719/21/4/015

Cited by 5 publications

(2 citation statements)

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“…Note that the optical spectrum of the two compounds is almost identical, except for the fine-structure splitting of some d-d transitions, which is however too tiny to be resolved by broadband femtosecond laser pulses. 37 Consequently, a straightforward comparison of the results obtained with these two samples can be carried out only based on their magnetic properties. Figure 7(a) reports the temperature dependence of the spin dynamics optically excited and detected in the time-domain in K 2 NiF 4 .…”

Section: Temperature Dependence Of the Femto-nanomagnonsmentioning

confidence: 99%

“…The dominant exchange interaction determines an antiparallel alignment of the Ni 2+ spins in the NiF 2 planes, via 180 • Ni-F-Ni bonds. 36,37 Even neglecting the interplane exchange interaction between the Ni 2+ ions in the ordered planes and the isolated Ni 2+ ion between the planes (which is at least one order of magnitude weaker than the in-plane exchange coupling 36 ), the bulk properties of this compound are properly described.…”

Section: B Materialsmentioning

confidence: 99%

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Laser-driven quantum magnonics and terahertz dynamics of the order parameter in antiferromagnets

et al. 2019

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The impulsive generation of two-magnon modes in antiferromagnets by femtosecond optical pulses, so-called femto-nanomagnons, leads to coherent longitudinal oscillations of the antiferromagnetic order parameter that cannot be described by a thermodynamic Landau-Lifshitz approach. We argue that this dynamics is triggered as a result of a laser-induced modification of the exchange interaction. In order to describe the oscillations we have formulated a quantum mechanical description in terms of magnon pair operators and coherent states. Such an approach allowed us to derive an effective macroscopic equation of motion for the temporal evolution of the antiferromagnetic order parameter. An implication of the latter is that the photo-induced spin dynamics represents a macroscopic entanglement of pairs of magnons with femtosecond period and nanometer wavelength. By performing magneto-optical pump-probe experiments with 10 femtosecond resolution in the cubic KNiF 3 and the uniaxial K 2 NiF 4 collinear Heisenberg antiferromagnets, we observed coherent oscillations at the frequency of 22 THz and 16 THz, respectively. The detected frequencies as a function of the temperature fit the two-magnon excitation up to the Néel point. The experimental signals are described as dynamics of magnetic linear dichroism due to longitudinal oscillations of the antiferromagnetic vector.

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Section: Temperature Dependence Of the Femto-nanomagnonsmentioning

confidence: 99%