TY - GEN
T1 - Electron-phonon coupling and polaronic effects in the high-Tc superconductor Ba1-xKxBiO3
AU - Naamneh, Muntaser
AU - Gawryluk, Dariusz
AU - Shang, Tian
AU - McNally, Daniel
AU - Dantz, Marcus
AU - Pelliciari, Jonathan
AU - Mesot, Joel
AU - Shi, Ming
AU - Radovic, Milan
AU - Schmitt, Thorsten
AU - Johnston, Steven
AU - Plumb, Nicholas
PY - 2018/3/5
Y1 - 2018/3/5
N2 - Ba1-xKxBiO3 (BKBO) is a phonon-mediated superconductor (max Tc 32 K) exhibiting many hallmarks of "unconventional" superconductivity. It is therefore an ideal system for exploring how electron-phonon interactions may give rise to unexpectedly high Tc's and other anomalous behaviors. In order to probe collective excitations in BKBO, we have performed resonant inelastic x-ray scattering (RIXS) at the O-K edge on thin films of BKBO in the doping range from x = 0 (insulator) to x = 0.4 (superconductor near optimal doping). The data have been analyzed by a cluster exact diagonalization approach, adapting a model successfully employed on 3d transition metal oxides to the s-p orbital system of BKBO. For all dopings, the extracted coupling constant exceeds a critical strength, beyond which bipolarons tend to become stabilized. The results help to quantify the polaronic nature of BKBO and imply that these compounds are susceptible to intrinsic disorder due to polaronic distortions across the entire investigated doping range. Implications for superconductivity will be discussed.
AB - Ba1-xKxBiO3 (BKBO) is a phonon-mediated superconductor (max Tc 32 K) exhibiting many hallmarks of "unconventional" superconductivity. It is therefore an ideal system for exploring how electron-phonon interactions may give rise to unexpectedly high Tc's and other anomalous behaviors. In order to probe collective excitations in BKBO, we have performed resonant inelastic x-ray scattering (RIXS) at the O-K edge on thin films of BKBO in the doping range from x = 0 (insulator) to x = 0.4 (superconductor near optimal doping). The data have been analyzed by a cluster exact diagonalization approach, adapting a model successfully employed on 3d transition metal oxides to the s-p orbital system of BKBO. For all dopings, the extracted coupling constant exceeds a critical strength, beyond which bipolarons tend to become stabilized. The results help to quantify the polaronic nature of BKBO and imply that these compounds are susceptible to intrinsic disorder due to polaronic distortions across the entire investigated doping range. Implications for superconductivity will be discussed.
M3 - Conference contribution
VL - 63 (1)
BT - APS March Meeting Abstracts 2018
CY - Los Angeles, California
ER -