Algebraic charge liquids
Abstract
High-temperature superconductivity emerges in the copper oxide compounds on changing the electron density of an insulator in which the electron spins are antiferromagnetically ordered. A key characteristic of the superconductor is that electrons can be extracted from it at zero energy only if their momenta take one of four specific values (the `nodal points'). A central enigma has been the evolution of those zero-energy electrons in the metallic state between the antiferromagnet and the superconductor, and recent experiments yield apparently contradictory results. The oscillation of the resistance in this metal as a function of magnetic field indicates that the zero-energy electrons carry momenta that lie on elliptical `Fermi pockets', whereas ejection of electrons by high-intensity light indicates that the zero-energy electrons have momenta only along arc-like regions, or `Fermi arcs'. We present a theory of new states of matter, which we call `algebraic charge liquids', and which arise naturally between the antiferromagnet and the superconductor, and reconcile these observations. Our theory also explains a puzzling dependence of the density of superconducting electrons on the total electron density, and makes a number of unique predictions for future experiments.
- Publication:
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Nature Physics
- Pub Date:
- January 2008
- DOI:
- 10.1038/nphys790
- arXiv:
- arXiv:0706.2187
- Bibcode:
- 2008NatPh...4...28K
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Superconductivity
- E-Print:
- 6+8 pages, 2 figures