Abstract: . . .  and bosonic modes. This change is manifested in the clear disappearance of coupling of the modes in the intermediate energy range (30–60 meV). We interpret this effect as caused by a dramatic change in the coupling to c -axis phonons, turning from polar into metallic in this doping regime. We stress that the presence of these polar EP interactions in an otherwise metallic system is highly un- usual and there have to be more surprises in store. We thank D. van der Marel and A. Damascelli for enlightening discussions and X.J. Zhou and W. L. Yang  . . .
. . .  modes may well lie hidden in the background and be less likely to be the cause for the strong change in this doping range. The next question is why the self-energy changes so much in this doping range? Although we are not aware of systematic measurements of the doping dependence of the electrodynamical properties along the c axis of Bi2201, comparison with other cuprates (the LSCO [25] and YBCO [26] systems) suggests that the screened loss function for OD system is reasonable. Optical measurements have re- vealed that the metallization . . .
. . .  Phys. Rev. B 71 , 060501 (2005). [21] A.A. Tsvetkov et al. , Phys. Rev. B 60 , 13196 (1999). [22] K.A. Muller and J.G. Bednorz, Science 237 , 1133 (1987). [23] W. Meevasana et al. (to be published). [24] H. Morawitz et al. , Z. Phys. B 90 , 277 (1993), and references therein. [25] S. Uchida et al. , Phys. Rev. B 53 , 14558 (1996). [26] S. Tajima et al. , Phys. Rev. B 55 , 6051 (1997). [27] S. Ono and Y. Ando, Phys. Rev. B 67 , 104512 (2003). [28] I. Chong et al. , Physica (Amsterdam) 290C , 57 (1997). PRL 96, 157003 (2006)  . . .
. . .  between OP and OD samples, reflecting a change in the coupling of electron and bosonic modes. This change is manifested in the clear disappearance of coupling of the modes in the intermediate energy range (30–60 meV). We interpret this effect as caused by a dramatic change in the coupling to c -axis phonons, turning from polar into metallic in this doping regime. We stress that the presence of these polar EP interactions in an otherwise metallic system is highly un- usual and there have to be more surprises in store. We thank D. van der Marel and A. . . .
. . .  0 : 15–0 : 30 [23]. Bi2201 does not seem to be an exception, given that for instance its c -axis resistivity reduces upon doping [27] and shows a metallic behavior in the OD sample [28]. In conclusion, we have found rather dramatic changes in the self-energy of nodal electrons between OP and OD samples, reflecting a change in the coupling of electron and bosonic modes. This change is manifested in the clear disappearance of coupling of the modes in the intermediate energy range (30–60 meV). We interpret this effect as caused by a dramatic . . .
--3000,5,300,3367,26069