Claesson T, Månsson M, Dallera C, Venturini F, De Nadaï C, Brookes N B, Tjernberg O
Laboratory of Materials and Semiconductor Physics, Royal Institute of Technology, Electrum 229, S-164 40 Kista, Sweden.
Phys Rev Lett. 2004 Sep 24;93(13):136402. doi: 10.1103/PhysRevLett.93.136402. Epub 2004 Sep 21.
We have performed an angle resolved photoemission study on a single crystal of the optimally electron doped (n-type) cuprate superconductor Nd2-xCexCuO4 (x=0.15) at a photon energy of 400 eV. The Fermi surface is mapped out and is, in agreement with earlier measurements, of hole-type with the expected Luttinger volume. However, comparing with previous low energy measurements, we observe a different Fermi surface shape and a different distribution of spectral intensity around the Fermi surface contour. The observed Fermi surface shape indicates a stronger electron correlation in the bulk as compared to the surface.
我们在光子能量为400电子伏特的条件下，对最佳电子掺杂（n型）铜酸盐超导体Nd2-xCexCuO4（x = 0.15）的单晶进行了角分辨光电子能谱研究。费米面已被描绘出来，与早期测量结果一致，其为具有预期卢廷格体积的空穴型。然而，与之前的低能测量结果相比，我们观察到费米面形状不同，且费米面轮廓周围的光谱强度分布也不同。观察到的费米面形状表明，与表面相比，体相中电子关联更强。
