Strong surface contribution to the nonlinear Meissner effect in d-wave superconductors

Area of Science:

• Condensed matter physics
• Superconductivity

Background:

• The nonlinear Meissner effect in superconductors is crucial for understanding their electromagnetic properties.
• D-wave superconductors exhibit unique electronic behaviors due to their unconventional pairing symmetry.

Purpose of the Study:

• To investigate the dominant mechanism behind the bulk nonlinear Meissner effect in d-wave superconductors at low temperatures.
• To elucidate the role of surface Andreev bound states in the nonlinear response.
• To establish the temperature dependence and characteristics of the surface contribution.

Main Methods:

• Numerical calculations were performed to model the nonlinear response.
• An approximate analytical calculation was developed to support numerical findings.
• The study focused on low-temperature behavior in d-wave superconductors.

Main Results:

• The bulk nonlinear Meissner effect is dominated by a surface effect originating from Andreev bound states at low temperatures.
• The surface effect's contribution to the nonlinear response coefficient follows a 1/T3 law, with a sign opposite to the bulk 1/T behavior.
• A crossover temperature, T/Tc∼1/sqrt(κ), marks the transition from bulk-dominated to surface-dominated behavior.

Conclusions:

• Surface Andreev bound states significantly influence the nonlinear Meissner effect in d-wave superconductors.
• The distinct temperature dependencies of bulk and surface effects allow for their differentiation.
• Intermodulation distortion experiments are proposed as a method to experimentally probe this surface effect.