Benhabib S, Sacuto A, Civelli M, Paul I, Cazayous M, Gallais Y, Méasson M-A, Zhong R D, Schneeloch J, Gu G D, Colson D, Forget A
Laboratoire Matériaux et Phénomènes Quantiques (UMR 7162 CNRS), Université Paris Diderot-Paris 7, Bâtiment Condorcet, 75205 Paris Cedex 13, France.
Laboratoire de Physique des Solides, UMR 8502 CNRS, Université Paris Sud, Bâtiment 510, 91405 Orsay Cedex, France.
Phys Rev Lett. 2015 Apr 10;114(14):147001. doi: 10.1103/PhysRevLett.114.147001. Epub 2015 Apr 7.
We report a fine tuned doping study of strongly overdoped Bi_{2}Sr_{2}CaCu_{2}O_{8+δ} single crystals using electronic Raman scattering. Combined with theoretical calculations, we show that the doping, at which the normal-state pseudogap closes, coincides with a Lifshitz quantum phase transition where the active holelike Fermi surface becomes electronlike. This conclusion suggests that the microscopic cause of the pseudogap is sensitive to the Fermi surface topology. Furthermore, we find that the superconducting transition temperature is unaffected by this transition, demonstrating that their origins are different on the overdoped side.
我们报告了一项使用电子拉曼散射对严重过掺杂的Bi₂Sr₂CaCu₂O₈₊δ单晶进行的精细掺杂研究。结合理论计算，我们表明，正常态赝能隙闭合时的掺杂与一个里夫希茨量子相变相吻合，此时活跃的类空穴费米面变为类电子费米面。这一结论表明，赝能隙的微观成因对费米面拓扑结构敏感。此外，我们发现超导转变温度不受此相变影响，这表明在过掺杂一侧它们的起源不同。
