Beck, M., Rousseau, I., Klammer, M., Leiderer, P., Mittendorff, M., Winnerl, S., et al. (2013). Transient increase of the energy gap of superconducting NbN thin films excited by resonant narrow-band terahertz pulses. Phys. Rev. Lett., 110(26), 267003 (1 to 5).
Abstract: Observations of radiation-enhanced superconductivity have thus far been limited to a few type-I superconductors (Al, Sn) excited at frequencies between the inelastic scattering rate and the superconducting gap frequency 2Delta/h. Utilizing intense, narrow-band, picosecond, terahertz pulses, tuned to just below and above 2Delta/h of a BCS superconductor NbN, we demonstrate that the superconducting gap can be transiently increased also in a type-II dirty-limit superconductor. The effect is particularly pronounced at higher temperatures and is attributed to radiation induced nonthermal electron distribution persisting on a 100 ps time scale.
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Bremer, J. W., & Newhouse, V. L. (1958). Phys. Rev. Lett., 1, 282.
|
|
Callen, H. B., & Welton, T. A. (1951). Irreversibility and generalized noise. Phys. Rev., 83(1), 34–40.
|
|
Rothwarf, A., & Taylor, B. N. (1967). Measurement of recombination lifetimes in superconductors. Phys. Rev. Lett., 19(1), 27–30.
|
|
Parker, W. H. (1975). Modified heating theory of nonequilibrium superconductors. Phys. Rev. B, 12(9), 3667–3672.
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