Unconventional superconductivity and paramagnetic Meissner response triggered by nonlocal pairing interaction in proximitized heterostructures

Abstract

Proximity phenomena and induced superconducting correlations in heterostructures are shown to be strongly affected by the nonlocal nature of the electronic attraction. The latter can trigger the formation of Cooper pairs consisting of electrons localized in neighbouring layers even in the absence of direct quasiparticle transfer between the layers. We investigate the manifestations of such nonlocal pairing and resulting unconventional induced superconductivity in an exemplary two-dimensional (2D) electronic system coupled to a conventional superconductor. The interplay between the quasiparticle tunneling and spin-triplet interlayer pairing is shown to generate the odd-frequency superconducting correlations in the 2D material which give rise to the paramagnetic contribution to the Meissner response and affect the energy resolved quasiparticle density of states. Experimental evidence for the above nonlocal interface pairing would provide new perspectives in engineering the unconventional superconducting correlations in heterostructures.