Is the nonlinear Meissner effect unobservable?

we show that the effects of nonlocal electrodynamics on a d-wave superconductor generically prevent the occurrence of a linear term in the field-dependent magnetic penetration depth, commonly known as the nonlinear Meissner effect. The field dependence is instead found to be quadratic, $\delta\lambda\sim H^2$ for fields below a crossover scale $H^\ast$ describing the competition between nonlinear and nonlocal effects in the Meissner state. Since this crossover is typically of the same order as or greater than $H_{c1}$, there is no range over which the nonlinear Meissner effect can be observed in generic experimental geometries.