The London penetration depth for the unconventional superconductor Sr2RuO4
is analyzed assuming an order parameter which breaks time-reversal symmetry
and parity simultaneously. Such a superconductor possesses gapless chiral
quasiparticle states at the surface. We show that these subgap states contr
ibute significantly to the low-temperature behavior of the London penetrati
on depth, yielding a T-2 power law even though bulk quasiparticle spectrum
is gapped. The presence of several electron bands gives rise to interband t
ransition among the subgap surface states and influences the properties of
the surface impedance. The surface states also lead to a nonlinear Meissner
effect.