Temperature Dependence of the Magnetic Penetration Depth in the Case of the Coexistence of Charge Density Waves and Superconductivity

Abstract

An analytical expression for the temperature dependence of the superfluid density in the regime of the coexistence of charge density waves (CDW) and superconductivity has been derived beyond the effective mass approximation. In contrast to the previous research on this subject, possible dispersions of both order parameters have been taken into account. In particular, it was found that when the CDW gap parameter depends on the wave vector, London’s type current is nonzero even above $T_\mathrm{c}$, i.e., in the interval $T_\mathrm{c}<T<T_\mathrm{CDW}$. The results of numerical calculations are discussed in the context of available experimental data for underdoped cuprates.