Dynamical triplet blockade in Andreev junction

We study the time-dependent Andreev blockade manifested under nonequilibrium conditions in a

nanoscopic junction comprising two quantum dots coupled in series between the superconducting and

metallic leads. This blockade would occur when both quantum dots are singly occupied by identical

spin electrons, preventing any charge transport in the subgap regime. Such situation is caused

by the inefficiency of the superconducting proximity effect. We investigate dynamical processes in

which this triplet configuration is temporarily imposed on the quantum dots by the initial conditions

before contacting ingredients of our hybrid structure. We next consider emergence of the Andreev

blockade driven by the external magnetic field and determine its duration upon biasing the junction.

Moreover, using the time-dependent numerical renormalization group technique, we also address

the Coulomb interactions and study their influence on the Andreev blockade in the presence of the

magnetic field. From analytical and numerical calculations, we infer the characteristic temporal

scales for the build-up and disappearance of the Andreev blockade, which could be verified by the

time-resolved tunneling spectroscopy measurements. The considered nonequilibrium features of the

Andreev blockade might play an important role for designing protocols on superconducting qubits

in their conventional and/or topological realizations.