Fig. 2: SHG and THG spectra of κ-(BEDT–TTF)2Cu[N(CN)2]Br, and their polarization and temperature dependences.
From: Petahertz non-linear current in a centrosymmetric organic superconductor
![Fig. 2: SHG and THG spectra of κ-(BEDT–TTF)2Cu[N(CN)2]Br, and their polarization and temperature dependences.](http://media.springernature.com/full/springer-static/image/art%3A10.1038%2Fs41467-020-17776-3/MediaObjects/41467_2020_17776_Fig2_HTML.png?as=webp)
a The red and green lines indicate the SHG spectra of single crystalline κ-(BEDT–TTF)2Cu[N(CN)2]Br (6 K) for the polarizations of (Efund | |c, ESH | | c) (red line) and (Efund | |a, ESH | | c) (green line, ×0.73). The blue line shows the THG spectrum (×0.024) for (Efund | |c, ETH | | c). The intensity of the fundamental light (Ifund = Efund2) is 2 mJ/cm2. Inset shows Ifund dependences of ISH (red line for Efund | |c, ESH | | c) and ITH (blue line for Efund | |c, ETH | | c). b Polarization dependences of ISH (upper panel) and ITH (lower panel) for Efund | |c (red line) and Efund | |a (green line), respectively. c Temperature dependences of ISH (closed red circles: Efund | |a, ESH | | c, open red circles: Efund | |c, ESH | | c) and ITH (open blue circles, Efund | |c, ETH | | c). Both are normalized by the respective intensities at 6 K. d SHG spectra (Efund | |a, ESH | | c) at 6 K (green line) and at 60 K (black dots).
