Evidence for two energy scales in the superconducting state of optimally doped (Bi,Pb)(2)(Sr,La)(2)CuO6+delta
| Title | Evidence for two energy scales in the superconducting state of optimally doped (Bi,Pb)(2)(Sr,La)(2)CuO6+delta |
| Publication Type | Journal Article |
| Year of Publication | 2007 |
| Authors | Kondo T, Takeuchi T, Kaminski A, Tsuda S, Shin S |
| Journal Title | Physical Review Letters |
| Volume | 98 |
| Pages | 267004 |
| Date Published | Jun |
| Type of Article | Article |
| ISBN Number | 0031-9007 |
| Accession Number | ISI:000247625100053 |
| Keywords | BI2SR2-XLAXCUO6+DELTA, COPPER-OXIDE METALS, critical-point, gap, liquid, phase, PHOTOEMISSION-SPECTROSCOPY, pseudogap, T-C SUPERCONDUCTORS |
| Abstract | We use angle-resolved photoemission spectroscopy to investigate the energy gap(s) in (Bi,Pb)(2)(Sr,La)(2)CuO6+delta. We find that the spectral gap has two components in the superconducting state: a superconducting gap and pseudogap. Differences in their momentum and temperature dependence suggest that they represent two separate energy scales. Spectra near the node reveal a sharp peak with a small gap below T-c that closes at T-c. Near the antinode, spectra are broad with a large energy gap of similar to 40 meV above and below T-c. The latter spectral shape and gap magnitude are almost constant across T-c, indicating that the pseudogap state coexists with the superconducting state below T-c, and it dominates spectra around the antinode. We speculate that the pseudogap state competes with the superconductivity by diminishing spectral weight in antinodal regions, where the superconducting gap is largest. |
| DOI | 10.1103/PhysRevLett.98.267004 |
| Alternate Journal | Phys. Rev. Lett. |
