The influence of chiral surface states on the London penetration depth in Sr${}_2$RuO${}_4$

Abstract

The London penetration depth for the unconventional superconductor Sr${}_2$RuO${}_4$ is analyzed assuming an order parameter which breaks time reversal symmetry and parity simultaneously. Such a superconducting state possesses chiral quasiparticle states with subgap energies at the surface. We show that these subgap states can give a significant contribution to the low-temperature behavior of the London penetration depth yielding a $T^2$ power-law even though bulk quasiparticle spectrum is gapped. The presence of several electron bands gives rise to interband transition among the subgap surface states and influences the properties of the surface impedance. Furthermore, the surface states lead also to a non-linear Meissner effect.

4 pages, 1 figure, the definition of the Nambu field operator introduced, and some typos corrected

References in corpus (2)

• Time-Reversal Symmetry Breaking Superconductivity in Sr2RuO4
• Quasiparticle States near the Surface and the Domain Wall in a p_x\pm i p_y-Wave Superconductor

Cited by in corpus (3)

• Josephson current between chiral superconductors
• The penetration depth in Sr2RuO4: Evidence for orbital dependent superconductivity
• Quantum transport signatures of chiral edge states in Sr${}_2$RuO${}_4$