Title :
Ultrafast photoexcited quasiparticle dynamics in YBCO films observed by THz emission
Author :
Hangyo, M. ; Tomozawa, S. ; Murakami, Y. ; Tonouchi, M. ; Tani, M. ; Wang, Z. ; Sakai, K.
Author_Institution :
Res. Center for Supercond. Mater. & Electron., Osaka Univ., Japan
fDate :
6/1/1997 12:00:00 AM
Abstract :
We observed a femtosecond time-transient nonequilibrium state in optically excited YBCO thin films for the first time. Ultrashort electromagnetic pulses were radiated from the films by an ultrafast supercurrent modulation with fs laser pulse irradiation. Quasiparticle dynamics was characterized by the analysis of the emission waveforms based on Rothwarf-Taylor rate equations.
Keywords :
barium compounds; high-speed optical techniques; high-temperature superconductors; quasiparticles; superconducting thin films; yttrium compounds; Rothwarf-Taylor rate equation; YBCO film; YBaCuO; femtosecond time-transient nonequilibrium state; laser pulse irradiation; quasiparticle dynamics; supercurrent modulation; terahertz radiation emission waveform; ultrafast optical excitation; ultrashort electromagnetic pulse; EMP radiation effects; Laser excitation; Optical films; Optical modulation; Optical pulses; Pulse modulation; Stimulated emission; Transistors; Ultrafast optics; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
