Publication Date
3-7-2019
Department
Ames Laboratory; Physics and Astronomy
Campus Units
Physics and Astronomy, Ames Laboratory
OSTI ID+
1546176
Report Number
IS-J 9913
DOI
10.1103/PhysRevB.99.094504
Journal Title
Physical Review B
Volume Number
99
Issue Number
9
First Page
094504
Abstract
We report terahertz (THz) electrodynamics of a moderately clean A15 superconductor (SC) following ultrafast excitation to manipulate quasiparticle (QP) transport. In the Martensitic normal state, we observe a photo enhancement in the THz conductivity using optical pulses, while the opposite is observed for the THz pump. This demonstrates wavelength-selective nonthermal control of conductivity distinct from sample heating. The photo enhancement persists up to an additional critical temperature, above the SC one, from a competing electronic order. In the SC state, the fluence dependence of pair-breaking kinetics together with an analytic model provides an implication for a “one photon to one Cooper pair” nonresonant energy transfer during the 35-fs laser pulse; i.e., the fitted photon energy ℏω absorption to create QPs set by 2ΔSC/ℏω=0.33%. This is more than one order of magnitude smaller than in previously studied BCS SCs, which we attribute to strong electron-phonon coupling and possible influence of phonon condensation.
DOE Contract Number(s)
AC02-07CH11358; FG02-06ER46327; SC0019137
Language
en
Publisher
Iowa State University Digital Repository, Ames IA (United States)
