Quantum phase transitions in the cuprate superconductor Bi2Sr2-xLaxCuO6+delta.
To elucidate a quantum phase transition (QPT) in Bi(2)Sr(2-x)La(x)CuO(6+delta), we measure charge and heat transport properties at very low temperatures and examine the following characteristics for a wide range of doping: normal-state resistivity anisotropy under 58 T, temperature dependence of the in-plane thermal conductivity kappa(ab), and the magnetic-field dependence of kappa(ab). It turns out that all of them show signatures of a QPT at the 1/8 hole doping. Together with the recent normal-state Hall measurements under 58 T that signified the existence of a QPT at optimum doping, the present results indicate that there are two QPTs in the superconducting doping regime of this material.
Ando
Yoichi
Y
Central Research Institute of Electric Power Industry, Komae, Tokyo 201-8511, Japan. ando@criepi.denken.or.jp
Ono
S
S
Sun
X F
XF
Takeya
J
J
Balakirev
F F
FF
Betts
J B
JB
Boebinger
G S
GS