Related papers: Singularity of the London penetration depth at qua…
The issue of whether the quantum critical point (QCP) is hidden inside unconventional superconductors is a matter of hot debate. Although a prominent experiment on London penetration depth has demonstrated the existence of the QCP in the…
In this work we study thermodynamic manifestations of the quantum criticality in multiband unconventional superconductors. As a guiding example we consider the scenario of magnetic quantum critical point in the model that captures…
Recent measurements of the doping dependence of the London penetration depth \lambda(x) at low temperatures in clean samples of isovalent BaFe_2[As_(1-x)P_x]_2 at T<<Tc [Hashimoto et al., Science 336, 1554 (2012)] revealed a peak in…
London penetration depth, $\lambda (T)$, was measured in single crystals of K$_{1-x}$Na$_x$Fe$_2$As$_2$, $x$=0 and 0.07, down to temperatures of 50~mK, $\sim T_c/50$. Isovalent substitution of Na for K significantly increases impurity…
We propose a comprehensive theoretical formulation of magnetic penetration depth, $\lambda(T)$, based on the microscopic calculations for a general superconducting gap symmetry. Our findings admit the significant role of band structure and…
In a superconductor, the ratio of the carrier density, $n$, to their effective mass, $m^*$, is a fundamental property directly reflecting the length scale of the superfluid flow, the London penetration depth, $\lambda_L$. In two dimensional…
The London penetration depth plays a key role in determining and uncovering many properties of a superconductor, including homogeneity, anisotropy, isotope effects, importance of quantum and thermal fluctuations, and facets of the nature of…
Recent high-precision measurements employing different experimental techniques have unveiled an anomalous peak in the doping dependence of the London penetration depth which is accompanied by anomalies in the heat capacity in iron-pnictide…
We present an analysis of previously published measurements of the London penetration depth of layered organic superconductors. The predictions of the BCS theory of superconductivity are shown to disagree with the measured zero temperature,…
The anisotropy of the London penetration depth is evaluated for two-band superconductors with arbitrary inter- and intra-band scattering times. If one of the bands is clean and the other is dirty in the absence of inter-band scattering, the…
We study the effect of disorder on the London penetration depth in iron-based superconductors. The theory is based on a two-band model with quasi-two-dimensional Fermi surfaces, which allows for the coexistence region in the phase diagram…
For multi-component superconductors, it is known that the presence of symmetry breaking fields can lead to multiple superconducting phase transitions. This phenomenon is best illustrated in UPt$_3$. Motivated by recent small angle neutron…
The in-plane London penetration depth, $\lambda(T)$, was measured in single crystals of the iron-chalcogenide superconductors Fe$_{1.03}$(Te$_{0.63}$Se$_{0.37}$) and Fe$_{1.06}$(Te$_{0.88}$S$_{0.14}$) by using a radio-frequency tunnel diode…
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 -…
This paper provides an explicit formula for the approximate solution of the static London equations. These equations describe the currents and magnetic fields in a Type-I superconductor. We represent the magnetic field as a 2-form and the…
Fascination with the concept of superconducting (SC) {\it superfluid density} $\rho_s$ has persisted since the beginning of superconductivity theory, with numerical values of an actual density rarely provided. Over time $\rho_s$, addressed…
The London penetration depth $\lambda$ is the basic length scale for electromagnetic behavior in a superconductor. Precise measurements of $\lambda$ as a function of temperature, field, and impurity scattering have been instrumental in…
It is shown that the thermodynamic Rutgers relation for the second order phase transitions can be used for the analysis of the superfluid density data irrespective of complexities of the Fermi surface, structure of the superconducting gap,…
The London penetration depth, $\lambda(T)$, has been measured in several single crystals of Ba(Fe$_{0.93}$Co$_{0.07}$)$_2$As$_2$. Thermodynamic, electromagnetic, and structural characterization measurements confirm that these crystals are…
We report measurements of the in-plane London penetration depth $\lambda$ in single crystals of the $\alpha$-PdBi$_{2}$ superconductor --- the $\alpha$-phase counterpart of the putative topological superconductor $\beta$-PdBi$_{2}$, down to…