Observation of an unconventional metal-insulator transition in overdoped CuO_2 compounds

• Main Authors: Venturini, F, Opel, M, Devereaux, T. P, Freericks, J. K, Tüttő, I, Revaz, B, Walker, E, Berger, H, Forró, L, Hackl, R
• Format: Journal Article
• Language: English
• Published: 12-06-2002
• Subjects: Physics - Strongly Correlated Electrons; Physics - Superconductivity
• DOI: 10.48550/arxiv.cond-mat/0206210

Phys. Rev. Lett. 89, 107003 (2002) The electron dynamics in the normal state of
Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ is studied by inelastic light scattering
over a wide range of doping. A strong anisotropy of the electron relaxation is
found which cannot be explained by single-particle properties alone. The
results strongly indicate the presence of an unconventional quantum-critical
metal-insulator transition where "hot" (antinodal) quasiparticles become
insulating while "cold" (nodal) quasiparticles remain metallic. A phenomenology
is developed which allows a quantitative understanding of the Raman results and
provides a scenario which links single- and many-particle properties.