Misbehaviour in metals

Allen, Philip B.

doi:10.1038/35016675

Cited by 11 publications

(7 citation statements)

References 5 publications

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“…1 and shows good agreement with the work of Lin et al [39]. This derivation neglects the contribution of electron-phonon momentum exchange and therefore neglects the effect of lattice temperature on energy transfer [42,43], which has been shown to increase by up to two orders of magnitude [44,45]. However, it has been shown that this T e -dependent electron-phonon coupling is capable of closely reproducing the temperature profiles for tungsten single crystals subject to irradiation by a 90 fs laser pulse [38].…”

Section: E (T E )supporting

confidence: 82%

Contribution of electronic excitation to the structural evolution of ultrafast laser-irradiated tungsten nanofilms

et al. 2016

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The redistribution of the electron density in a material during laser irradiation can have a significant impact on its structural dynamics. This electronic excitation can be incorporated into two temperature molecular dynamics (2T-MD) simulations through the use of electronic temperature dependent potentials. Here, we study the structural dynamics of laser irradiated tungsten nanofilms using 2T-MD simulations with an electronic temperature dependent potential and compare the results to equivalent simulations that employ a ground-state interatomic potential. Electronic excitation leads to an expansion of the crystal and a decrease in the melting point of tungsten. During laser irradiation these factors ensure that the threshold fluences to the different melting regimes are reduced. Furthermore, both heterogenous and homogeneous melting are predicted to occur more rapidly due to excitation and oscillations in the film thickness will be accentuated.

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Section: E (T E )supporting

confidence: 82%

Contribution of electronic excitation to the structural evolution of ultrafast laser-irradiated tungsten nanofilms

et al. 2016

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“…2 include semiclassical pictures that invoke the existence of a minimum scattering time ( 10 , 28 ) as well as interband scattering ( 29 ) that acts as a new conducting channel ( 12 , 29 ). As has also been pointed out in the literature ( 11 , 12 , 32 ), it is questionable to use semiclassical arguments in a regime where l is not a well-defined quantity anymore. Quantum Monte Carlo and dynamical mean field theory calculations indicate that resistances can easily exceed the ρ MIR value calculated from Eq.…”

Section: Resultsmentioning

confidence: 99%

Tuning bad metal and non-Fermi liquid behavior in a Mott material: Rare-earth nickelate thin films

et al. 2015

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“…This happens when the apparent mean free path l becomes comparable to the separation, d, of two atoms, the Ioffe-Regel condition [16]. This kind of behavior has been observed for many metals and it used to be considered a universal behavior [17].The metals mentioned above and the alkali-doped fullerenes [18] are apparent exceptions to this saturation behavior, with the cuprates forming a particular challenge [19,20]. The deviation from the "universal" behavior can be illustrated by considering Ioffe-Regel condition for La 2−x Sr x CuO 4 .…”

mentioning

confidence: 99%

“…The metals mentioned above and the alkali-doped fullerenes [18] are apparent exceptions to this saturation behavior, with the cuprates forming a particular challenge [19,20]. The deviation from the "universal" behavior can be illustrated by considering Ioffe-Regel condition for La 2−x Sr x CuO 4 .…”

mentioning

confidence: 99%

Violation of Ioffe-Regel condition but saturation of resistivity of the high- T _c cuprates

Calandra

Gunnarsson

2003

Europhys. Lett.

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We demonstrate that the resistivity data of a number of high Tc cuprates, in particular La2−xSrxCuO4, are consistent with resistivity saturation, although the Ioffe-Regel condition is strongly violated. By using the f-sum rule together with calculations of the kinetic energy in the t − J model, we show that the saturation resistivity is unusually large. This is related to the strong reduction of the kinetic energy due to strong correlation effects. The fulfilment of the Ioffe-Regel condition for conventional transition metal compounds is found to be somewhat accidental.Some strongly correlated metals [1][2][3][4], in particular many high T c cuprates [5][6][7][8][9][10][11][12][13][14], show an exceptionally large resistivity, ρ, at high temperatures T . Thus ρ can reach values of several mΩcm. This is in strong contrast to almost all other metals. Typically, a metal with a very large resistivity shows resistivity saturation [15]. Thus when ρ reaches values of the order 0.1 mΩcm, the slope of ρ(T ) is typically reduced substantially, although not necessarily to zero. This happens when the apparent mean free path l becomes comparable to the separation, d, of two atoms, the Ioffe-Regel condition [16]. This kind of behavior has been observed for many metals and it used to be considered a universal behavior [17].The metals mentioned above and the alkali-doped fullerenes [18] are apparent exceptions to this saturation behavior, with the cuprates forming a particular challenge [19,20]. The deviation from the "universal" behavior can be illustrated by considering Ioffe-Regel condition for La 2−x Sr x CuO 4 . We assume a "large" Fermi surface of cylindrical shape, containing 1 − x electrons (or 1 + x holes) [21]. Assuming that l = a, where a is the lattice parameter in the CuO 2 plane, we obtain the saturation resistivityIf we instead assume a "small" Fermi surface, √ 1 ± x in the denominator is replaced by √ x. In either case, the experimental resistivity for small x is much larger than the saturation resistivity above, supporting the conclusion that there is no saturation in these systems.Here we demonstrate that the experimental data for the strongly correlated high T c cuprates are, nevertheless, consistent with saturation. The saturation resistivity can, however, be much larger than the Ioffe-Regel value. This is not entirely surprising, since the Ioffe-Regel condition is based on a semiclassical picture, which is not valid when l ∼ d. The good agreement between the IoffeRegel condition and the saturation for weakly correlated transition metal compounds is therefore somewhat accidental. The large saturation resistivity is shown to be due to a large reduction of the kinetic energy, due to strong correlation effects. Since the alkali-doped fullerenes appear to lack saturation [22], this puts these compounds in a special class, different from the cuprates.To discuss resistivity saturation, we use the f-sum rule in a form appropriate for the models discussed here (only nearest neighbor hopping and no on-site matrix ele...

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Misbehaviour in metals

Cited by 11 publications

References 5 publications

Contribution of electronic excitation to the structural evolution of ultrafast laser-irradiated tungsten nanofilms

Contribution of electronic excitation to the structural evolution of ultrafast laser-irradiated tungsten nanofilms

Tuning bad metal and non-Fermi liquid behavior in a Mott material: Rare-earth nickelate thin films

Violation of Ioffe-Regel condition but saturation of resistivity of the high- T _c cuprates

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Misbehaviour in metals

Cited by 11 publications

References 5 publications

Contribution of electronic excitation to the structural evolution of ultrafast laser-irradiated tungsten nanofilms

Contribution of electronic excitation to the structural evolution of ultrafast laser-irradiated tungsten nanofilms

Tuning bad metal and non-Fermi liquid behavior in a Mott material: Rare-earth nickelate thin films

Violation of Ioffe-Regel condition but saturation of resistivity of the high- T c cuprates

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Violation of Ioffe-Regel condition but saturation of resistivity of the high- T _c cuprates