相关论文: Isotope effect on the superfluid density in conven…
Superconducting gap structure was probed in type-II Dirac semimetal PdTe$_2$ by measuring the London penetration depth using tunnel diode resonator technique. At low temperatures, the data for two samples are well described by weak coupling…
Measurements of London penetration depth are a sensitive tool to study multi-band superconductivity and it has provided several important insights to the behavior of Fe-based superconductors. We first briefly review the "experimentalist -…
London, $\lambda_L (T)$, and Campbell, $\lambda_{C} (T)$, penetration depths were measured in single crystals of a topological superconductor candidate $\text{AuSn}_4$. At low temperatures, $\lambda_L (T)$ is exponentially attenuated and,…
Irradiation with Pb ions was used to study the effect of disorder on the in-plane London penetration depth, $\lambda(T)$, in single crystals of Ba(Fe$_{1-x}$T$_x$)$_2$As$_2$ (T=Co, Ni). An increase of the irradiation dose results in a…
The isotope coefficient $\beta$ of the magnetic penetration depth in the superconducting state is studied at T=0 for a $d$-CDW and a nodal metal model. Disregarding superconductivity the Fermi surface of the first model possesses arcs…
We report measurements of London penetration depth $\lambda(T)$ for the noncentrosymmetric superconductor BiPd by using a tunnel diode oscillator. Pronounced anisotropic behavior is observed in the low-temperature penetration depth; the…
The London penetration depth is evaluated for isotropic materials for any transport and pair-breaking Born scattering rates. Besides known results, a number of new features are found. The slope $|d\rho/d\theta |$ of the normalized…
We study the basic thermodynamic and electromagnetic properties of the superconductor described by the negative-$U$ Hubbard model (gap parameter $\Delta$, critical temperature $T_c$, London penetration depth $\lambda$, thermodynamic…
The in-plane penetration depth \lambda(T) is measured in electron-doped single crystals Nd1.85Ce0.15CuO4-x (NCCO) and Pr1.85Ce0.15CuO4-x (PCCO) using a 11 MHz LC resonator. In NCCO, \lambda(T) exhibits a minimum at 3.8 K and a pronounced…
Although the isotope effect in superconducting materials is well-documented, changes in the magnetic properties of antiferromagnets due to isotopic substitution are seldom discussed and remain poorly understood. This is perhaps surprising…
The oxygen-isotope (^{16}O/^{18}O) effect (OIE) on the in-plane magnetic penetration depth \lambda_{ab}(0) in optimally-doped YBa_2Cu_3O_{7-\delta} and La_{1.85}Sr_{0.15}CuO_4, and in slightly underdoped YBa_2Cu_4O_8 and…
We use inelastic neutron scattering to probe magnetic excitations of an optimally electron-doped superconductor Nd$_{1.85}$Ce$_{0.15}$CuO$_{4-\delta}$ above and below its superconducting transition temperature $T_c=25$ K. In addition to…
In this paper we calculate ab initially the phonon dispersion relationship of the superconductor LaFeAsO and investigate a main property in the superconductor, the oxygen isotope effect. Based on this phonon dispersion relationship, we find…
Isotope effect with a large coefficient $\alpha=-\partial \ln T_c/\partial \ln M$ is usually taken as an evidence of phonon mediated superconductors in the Bardeen-Cooper-Schrieffer (BCS) theory. However, in cuprates which are now widely…
In this article we review essential natures of superconductivity in strongly correlated electron systems (SCES) from a universal point of view. After summarizing experimental results on typical materials such as high-$T_{\rm c}$ cuprates,…
Superconductivity in the topological non-trivial Dirac semimetal PdTe$_2$ was recently shown to be type-I. We here report measurements of the relative magnetic penetration depth, $ \Delta \lambda$, on several single crystals using a high…
Muon-spin rotation (muSR) studies of the oxygen isotope (^{16}O/^{18}O) effect (OIE) on the in-plane magnetic field penetration depth lambda_{ab} in cuprate high-temperature superconductors (HTS) are presented. First, the doping dependence…
We report measurements of the temperature dependence of both in-plane and out-of-plane penetration depths ($\lambda_a$ and $\lambda_c$ respectively) in 2\textit{H}-NbSe$_2$. Measurements were made with a radio-frequency tunnel diode…
London and Campbell penetration depths were measured in single crystals of the endohedral gallide cluster superconductor, Mo$_{8}$Ga$_{41}$. The full temperature range superfluid density is consistent with the clean isotropic $s-$wave…
Using the large-$N$ limit of the $t$-$J$ model and allowing also for phonons and the electron-phonon interaction we study the isotope effect $\alpha$ for coupling constants appropriate for YBCO. We find that $\alpha$ has a minimum at…