Distinct quasiparticle relaxation dynamics in an electron-doped superconductor, BaFe1.9Ni0.1As2

Gong, Yu; Lai, Wei; Nosach, Tetiana; Li, L J; Cao, Guanghan; Xu, Zhu-An; Ren, Yuhang

doi:10.1088/1367-2630/12/12/123003

Cited by 14 publications

(17 citation statements)

References 33 publications

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“…The three-band Eliashberg model adequately describes experimental temperature dependences of the superfluid density and penetration depth of the BaFe 1.91 Ni 0.09 As 2 film. The calculated values of the larger gaps fall within the range reported in [6,7,8,9,10], the smaller gap correlates well with that found in [10]. The London penetration depth found in [5] for a BaFe 1.9 Ni 0.1 As 2 film was somewhat smaller (λ L ∼ 226 ± 20 nm) compared to the present study, which can be ascribed to the different composition of our film.…”

Section: Discussionsupporting

confidence: 90%

THz electrodynamics of BaFe_1.91Ni_0.09As₂ film analyzed in the framework of multiband Eliashberg theory

Ummarino¹,

Muratov²,

Kadyrov³

et al. 2020

Supercond. Sci. Technol.

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The temperature dependences of the plasma frequency, superfluid density and London penetration depth were determined from terahertz spectra of conductivity and dielectric permittivity of BaFe 1.91 Ni 0.09 As 2 film with critical temperature T c = 19.6 K. Part of experimental data were analyzed within a simple three-band Eliashberg model where the mechanism of superconducting coupling is mediated by antiferromagnetic spin fluctuations, whose characteristic energy Ω 0 scales with T c according to the empirical law Ω 0 = 4.65k B T c , and with a total electron-boson coupling strength λ tot = 2.17.

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Section: Discussionsupporting

confidence: 90%

THz electrodynamics of BaFe_1.91Ni_0.09As₂ film analyzed in the framework of multiband Eliashberg theory

Ummarino¹,

Muratov²,

Kadyrov³

et al. 2020

Supercond. Sci. Technol.

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“…Time domain optical spectroscopy has been, among other spectroscopies, very instrumental in elucidating the nature of the unusual normal state in the cuprates by virtue of the fact that different components in the lowenergy excitation spectrum could be distinguished by their different lifetimes. [18][19][20][21][22][23][24] In iron pnictides several reports on photoexcited carrier dynamics exist 8,[25][26][27][28][29][30][31][32] , but doping dependence studies are still incomplete 26,28,32 .…”

Section: Introductionmentioning

confidence: 99%

Doping dependence of femtosecond quasiparticle relaxation dynamics in Ba(Fe,Co)2As2single crystals: Evidence for normal-state nematic fluctuations

et al. 2012

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We systematically investigate the photoexcited (PE) quasi-particle (QP) relaxation and lowenergy electronic structure in electron doped Ba(Fe1−xCox)2As2 single crystals as a function of Co doping, 0 ≤ x ≤ 0.11. The evolution of the photoinduced reflectivity transients with x proceeds with no abrupt changes. In the orthorhombic spin-density-wave (SDW) state a bottleneck associated with a partial charge-gap opening is detected, similar to previous results in different SDW iron-pnictides. The relative charge gap magnitude 2∆(0)/kBTs decreases with increasing x. In the superconducting (SC) state an additional relaxational component appears due to a partial (or complete) destruction of the SC state proceeding on a sub-0.5-picosecond timescale. From the SC component saturation behavior the optical SC-state destruction energy, Up/kB = 0.3 K/Fe, is determined near the optimal doping. The subsequent relatively slow recovery of the SC state indicates clean SC gaps. The T -dependence of the transient reflectivity amplitude in the normal state is consistent with the presence of a pseudogap in the QP density of states. The polarization anisotropy of the transients suggests that the pseudogap-like behavior might be associated with a broken 4-fold rotational symmetry resulting from nematic electronic fluctuations persisting up to T ≃ 200 K at any x. The second moment of the Eliashberg function, obtained from the relaxation rate in the metallic state at higher temperatures, indicates a moderate electron phonon coupling, λ 0.3, that decreases with increasing doping.

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“…Various experimental studies have revealed multiple charge gaps in the superconducting state [4][5][6][7][8][9][10]. In the last couple of years, femtosecond time-resolved studies on iron pnictides, mostly on Sm-1111 [11,12] and Ba-122 [13][14][15][16][17][18] type pnictides have provided valuable information on the electronic relaxation dynamics, the multi-band structure and electron-phonon coupling. The common result among these studies is the observation of two electronic relaxation components with decay times from sub-ps to few ps in the spin density wave (SDW) and the superconducting (SC) states whose temperature and fluence-dependences were partly described using the phonon-bottleneck Routhwarf-Taylor (R-T) model [19].…”

Section: Introductionmentioning

confidence: 99%

Ultrafast quasiparticle relaxation dynamics in superconducting iron pnictide Ca(Fe0.944Co0.056)2As2

Kumar

Harnagea

Wurmehl

et al. 2013

Solid State Communications

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Nonequilibrium quasiparticle relaxation dynamics is reported in superconducting CaFe 1.89 Co 0.11 As 2 single crystal using femtosecond time-resolved pump-probe spectroscopy. The quasiparticle dynamics reflects a three-channel decay of laser deposited energy with characteristic time scales varying from few hundreds of femtoseconds to order of few nanoseconds where the amplitudes and time-constants of the individual electronic relaxation components show significant changes in the vicinity of the spin density wave (T SDW ~ 85 K) and superconducting (T SC ~ 20 K) phase transition temperatures. The quasiparticles dynamics in the superconducting state reveals a charge gap with reduced gap value of 2 0 /k B T SC ~ 1.8. We have determined the electron-phonon coupling constant  to be ~ 0.14 from the temperature dependent relaxation time in the normal state, a value close to those reported for other types of pnictides. From the peculiar temperature-dependence of the quasiparticle dynamics in the intermediate temperature region between the superconducting and spin density wave phase transitions, we infer a temperature scale where the charge gap associated with the spin ordered phase is maximum and closes on either side while approaching the two phase transition temperatures.

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Distinct quasiparticle relaxation dynamics in an electron-doped superconductor, BaFe_1.9Ni_0.1As₂

Cited by 14 publications

References 33 publications

THz electrodynamics of BaFe_1.91Ni_0.09As₂ film analyzed in the framework of multiband Eliashberg theory

THz electrodynamics of BaFe_1.91Ni_0.09As₂ film analyzed in the framework of multiband Eliashberg theory

Doping dependence of femtosecond quasiparticle relaxation dynamics in Ba(Fe,Co)2As2single crystals: Evidence for normal-state nematic fluctuations

Ultrafast quasiparticle relaxation dynamics in superconducting iron pnictide Ca(Fe0.944Co0.056)2As2

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Distinct quasiparticle relaxation dynamics in an electron-doped superconductor, BaFe1.9Ni0.1As2

Cited by 14 publications

References 33 publications

THz electrodynamics of BaFe1.91Ni0.09As2 film analyzed in the framework of multiband Eliashberg theory

THz electrodynamics of BaFe1.91Ni0.09As2 film analyzed in the framework of multiband Eliashberg theory

Doping dependence of femtosecond quasiparticle relaxation dynamics in Ba(Fe,Co)2As2single crystals: Evidence for normal-state nematic fluctuations

Ultrafast quasiparticle relaxation dynamics in superconducting iron pnictide Ca(Fe0.944Co0.056)2As2

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Distinct quasiparticle relaxation dynamics in an electron-doped superconductor, BaFe_1.9Ni_0.1As₂

THz electrodynamics of BaFe_1.91Ni_0.09As₂ film analyzed in the framework of multiband Eliashberg theory

THz electrodynamics of BaFe_1.91Ni_0.09As₂ film analyzed in the framework of multiband Eliashberg theory