Angular dependence of the penetration depth in unconventional superconductors

Abstract

We examine the Meissner state nonlinear electrodynamic effects on the field and angular dependence of the low temperature penetration depth, $\lambda$, of superconductors in several kinds of unconventional pairing states, with nodes or deep minima (``quasinodes'') in the energy gap. Our calculations are prompted by the fact that, for typical unconventional superconducting material parameters, the predicted size of these effects for $\lambda$ exceeds the available experimental precision for this quantity by a much larger factor than for others. We obtain expressions for the nonlinear component of the penetration depth, $\Delta \lambda$, for different two- and three- dimensional nodal or quasinodal structures. Each case has a characteristic signature as to its dependence on the size and orientation of the applied magnetic field. This shows that $\Delta \lambda$ measurements can be used to elucidate the nodal or quasinodal structure of the energy gap. For nodal lines we find that $\Delta \lambda$ is linear in the applied field, while the dependence is quadratic for point nodes. For layered materials with $\mathrm{YB}{\mathrm{a}}_2\mathrm{C}{\mathrm{u}}_3{\mathrm{O}}_{7-\delta }$ (YBCO) type anisotropy, our results for the angular dependence of $\Delta \lambda$ differ greatly from those for tetragonal materials and are in agreement with experiment. For the two- and three- dimensional quasinodal cases, $\Delta \lambda$ is no longer proportional to a power of the field and the field and angular dependences are not separable, with a suppression of the overall signal as the node is filled in.

16 pages plus nine figures

References in corpus (8)

• The Order Parameter for the Superconducting Phases of UPt${}_3$
• Evidence for nodal quasiparticles in electron-doped cuprates from penetration depth measurements
• Low Temperature Penetration depth of κ-(ET)_2Cu[N(CN)_2]Br and κ-(ET)_2Cu(NCS)_2
• Microwave Electrodynamics of Electron-Doped Cuprate Superconductors
• Details of disorder matter in 2D d-wave superconductors
• Spin waves in a two dimensional p-wave superconductor: Sr${}_2$RuO${}_4$
• Magnetic field effects on the density of states of orthorhombic superconductors
• Nonlinear electrodynamics of p-wave superconductors

Cited by in corpus (3)

• Midgap edge states and pairing symmetry of quasi-one-dimensional organic superconductors
• Cubic spin-orbit coupling and anomalous Josephson effect in planar junctions
• Has the nonlinear Meissner effect been observed?