相关论文: Homes scaling and BCS

The solutions of a renormalized BCS equation are studied in three space dimensions in $s$, $p$ and $d$ waves for finite-range separable potentials in the weak to medium coupling region. In the weak-coupling limit, the present BCS model…

The solutions of a renormalized BCS model are studied in two space dimensions in $s$, $p$ and $d$ waves for finite-range separable potentials. The gap parameter, the critical temperature $T_c$, the coherence length $\xi$ and the jump in…

Beginning with high-$T_c$ cuprate materials, it has been observed that many superconductors exhibit so-called "Homes scaling", in which the zero-temperature superfluid density, $\rho_{s0}$, is proportional to the product of the normal-state…

In our brief review, we will consider the general universal scaling properties of superconductors. The physics of superconductors, represented by both conventional and unconventional superconductors, has been the main topic of high-$T_c$…

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…

Theoretically, we recently showed that the scaling relation between the transition temperature T_c and the superfluid density at zero temperature n_s (0) might exhibit a parabolic pattern [Scientific Reports 6 (2016) 23863]. It is…

A scaling relation \rho_s \simeq 35\sigma_{dc}T_c has been observed in the copper-oxide superconductors, where \rho_s is the strength of the superconducting condensate, T_c is the critical temperature, and \sigma_{dc} is the normal-state dc…

A universal scaling relation, $\rho_s \propto \sigma(T_c)\times T_c$ has been reported by Homes $et$ $al$. (Nature (London) {\bf 430}, 539 (2004)) where $\rho_s$ is the superfluid density and $\sigma(T)$ is the DC conductivity. The relation…

Homes' law, $\rho_s = C \sigma_{\mathrm{DC}} T_c$, is an empirical law satisfied by various superconductors with a material independent universal constant $C$, where $\rho_{s}$ is the superfluid density at zero temperature, $T_c$ is the…

We measure the magnetic penetration depth $\Delta\lambda(T)$ for NdO$_{1-x}$F$_{x}$BiS$_{2}$ ($x$ = 0.3 and 0.5) using the tunnel diode oscillator technique. The $\Delta\lambda(T)$ shows an upturn in the low-temperature limit which is…

Based on recent progress in mathematical physics, we present a reliable method to analytically solve the linearized BCS gap equation for a large class of finite-range interaction potentials leading to s-wave superconductivity. With this…

Homes' law, $\rho_{s} = C \, \sigma_{DC} \, T_{c}$, is a universal relation of superconductors between the superfluid density $\rho_{s}$ at zero temperature, the critical temperature $T_{c}$ and the electric DC conductivity $\sigma_{DC}$ at…

It is a remarkable property of BCS theory that the ratio of the energy gap at zero temperature $\Xi$ and the critical temperature $T_c$ is (approximately) given by a universal constant, independent of the microscopic details of the…

The absolute values of the conductivity in the normal state sigma_n and of the low temperature penetration depths lambda(0) were measured for a number of different samples of the YBaCuO family. We found a striking correlation between…

In this paper we demonstrate how, using a natural generalization of BCS theory, superconducting phase coherence manifests itself in phase insensitive measurements, when there is a smooth evolution of the excitation gap \Delta from above to…

We present research on the superconducting properties of Nb$_{x}$Re$_{1-x}$ ($x$ = 0.13-0.38) obtained by measuring the electrical resistivity $\rho(T)$, magnetic susceptibility $\chi(T)$, specific heat $C_P(T)$, and London penetration…

Scaling relations between the superconducting transition temperature $T_{\rm c}$, the superfluid stiffness $\rho_{\rm s}$ and the normal state conductivity $\sigma_0(T_{\rm c})$ are identified within the class of molecular superconductors.…

A simple relation is established between the zero-$T$ penetration depth $\lambda (0)$ and the slope of $\lambda^{-2}(T)$ near $T_c$, similar to Helfand-Werthamer's relation for $H_{c2}(0)$ and the slope of $H_{c2}(T)$ at $T_c$ for the…

We develop a general description of the superconductivity of lattice fermions based on the BCS theory. We propose a modeling of the density of states (DOS) of lattice fermions, where divergent and semi-metallic structures are described by…

We consider the BCS energy gap $\Xi(T)$ (essentially given by $\Xi(T) \approx \Delta(T, \sqrt\mu)$, the BCS order parameter) at all temperatures $0 \le T \le T_c$ up to the critical one, $T_c$, and show that, in the limit of weak coupling,…