Pseudogap, superconducting energy scale, and Fermi arcs of underdoped cuprate superconductors

Article

关键词: DENSITY-OF-STATES;    D-WAVE SUPERCONDUCTORS;    QUASI-PARTICLES;    VORTEX STATE;    HEAT;    LA2-XSRXCUO4;    YBA2CU3O7-DELTA;   

DOI  :  10.1103/PhysRevB.72.134507

来源: SCIE

【 摘 要 】

Through the measurements of magnetic field dependence of specific heat in La2-xSrxCuO4 in zero temperature limit, we determined the nodal slope v(Delta) of the quasiparticle gap. It is found that v(Delta) has a very similar doping dependence of the pseudogap temperature T-* or value Delta(p). Meanwhile the virtual maximum gap at (pi,0) derived from v(Delta) is found to follow the simple relation Delta(q)=0.46k(B)T(*) upon changing the doping concentration. This strongly suggests a close relationship between the pseudogap and superconductivity. It is further found that the superconducting transition temperature is determined by both the residual density of states of the pseudogap phase and the nodal gap slope in the zero temperature limit, namely, T-c approximate to beta v(Delta)gamma(n)(0), where gamma(n)(0) is the extracted zero temperature value of the normal state specific heat coefficient which is proportional to the size of the residual Fermi arc k(arc). This shows that the superconductivity may be formed by forming a new gap on the Fermi arcs near nodes below T-c. These observations mimic the key predictions of the SU(2) slave boson theory based on the general resonating-valence-bond picture.

【 授权许可】

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