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Metal-to-Insulator Crossover in YBa_{2}Cu_{3}O_{y} Probed by Low-Temperature Quasiparticle Heat Transport

X. F. Sun·Kouji Segawa·Yoichi Ando
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Abstract

It was recently demonstrated that in La_{2-x}Sr_{x}CuO_{4} the magnetic-field (H) dependence of the low-temperature thermal conductivity κup to 16 T reflects whether the normal state is a metal or an insulator. We measure the H dependence of κin YBa_{2}Cu_{3}O_{y} (YBCO) at subkelvin temperatures for a wide doping range, and find that at low doping the κ(H) behavior signifies the change in the ground state in this system as well. Surprisingly, the critical doping is found to be located deeply inside the underdoped region, about the hole doping of 0.07 hole/Cu; this critical doping is apparently related to the stripe correlations as revealed by the in-plane resistivity anisotropy.

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X. F. Sun, Kouji Segawa, Yoichi Ando. 2004-07-20. Metal-to-Insulator Crossover in YBa_{2}Cu_{3}O_{y} Probed by Low-Temperature Quasiparticle Heat Transport. https://doi.org/10.1103/physrevlett.93.107001

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