Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

1 Publication

Possible Eliashberg-Type Superconductivity Enhancement Effects in a Two-Band Superconductor MgB2 Driven by Narrow-Band THz Pulses

Sobolev, S.; Lanz, A. P.; Dong, T.; Pokharel, A.; Kabanov, V.; Xu, T.-Q.; Wang, Y.; Gan, Z.-Z.; Shi, L.-Y.; Wang, N.-L.; Pashkin, O.; Uykur, E.; Winnerl, S.; Helm, M.; Demsar, J.


We study THz-driven condensate dynamics in epitaxial thin films of MgB2, a prototype two-band superconductor (SC) with weak interband coupling. The temperature and excitation density dependent dynamics follow the behavior predicted by the phenomenological bottleneck model for the single-gap SC, implying adiabatic coupling between the two condensates on the ps timescale. The amplitude of the THz-driven suppression of condensate density reveals an unexpected decrease in pair-breaking efficiency with increasing temperature—unlike in the case of optical excitation. The reduced pair-breaking efficiency of narrow-band THz pulses, displaying minimum near ≈0.7  Tc, is attributed to THz-driven, long-lived, nonthermal quasiparticle distribution, resulting in Eliashberg-type enhancement of superconductivity, competing with pair breaking.

Involved research facilities

Related publications



Years: 2023 2022 2021 2020 2019 2018 2017 2016 2015