Microwave and millimeter wave spectroscopy in the slightly hole-doped ladders of Sr 14 Cu 24 O 41

Abstract
We have measured the temperature and frequency dependence of the microwave and millimeter wave conductivity σ1(T,ω) along both the ladder (c-axis) and the leg (a-axis) directions in Sr14Cu24O41. Below a temperature T* ( ~ 170 K), we observed a stronger frequency dependence in σ1c(T,ω) than that in σ1a(T,ω), forming a small resonance peak developed between 30 GHz and 100 GHz. We also observed nonlinear dc conduction along the c-axis at rather low electric fields below T*. These results suggest some collective excitation contributes to the c-axis charge dynamics of the slightly hole-doped ladders of Sr14Cu24O41 below T*.
All Related Versions