EurekAlert November 12, 2024
An international team of researchers (India, USA – Indiana University) studied the transport signatures of unpaired Floquet Majorana fermions in the Josephson current of weakly linked, periodically driven topological superconductors. They obtained analytical expressions for the occupation of the Floquet Majorana fermions in the presence of weak coupling to thermal reservoirs, and showed that, similar to undriven topological superconductors, for sufficiently low temperatures and large systems the Josephson current involving Floquet Majorana fermions is in the phase difference across the junction and depends linearly on the coupling between superconductors. Unlike the static case, the amplitude of the Josephson current could be tuned by setting the unbiased chemical potential of the driven superconductors at multiple harmonics of the drive frequency. According to the researchers they uncovered a “Josephson Floquet sum rule” for driven superconductors. They confirmed their analytical expressions for Josephson current, the occupation of Floquet bands, and a perturbative analysis of the quasienergies with numerically exact results… read more. Open Access TECHNICAL ARTICLE
(a) Current-phase relationship for the Josephson junction between two driven Kitaev chains… Credit: Phys. Rev. Lett. 133, 196601,6 November 2024