How Cooper pairs vanish approaching the Mott insulator in Bi2Sr2CaCu2O8+d

Abstract

The antiferromagnetic ground state of copper oxide Mott insulators is achieved by localizing an electron at each copper atom in real space (r-space). Removing a small fraction of these electrons (hole doping) transforms this system into a superconducting fluid of delocalized Cooper pairs in momentum space (k-space). During this transformation, two distinctive classes of electronic excitations appear. At high energies, the enigmatic 'pseudogap' excitations are found, whereas, at lower energies, Bogoliubov quasi-particles -- the excitations resulting from the breaking of Cooper pairs -- should exist. To explore this transformation, and to identify the two excitation types, we have imaged the electronic structure of Bi2Sr2CaCu2O8+d in r-space and k-space simultaneously. We find that although the low energy excitations are indeed Bogoliubov quasi-particles, they occupy only a restricted region of k-space that shrinks rapidly with diminishing hole density. Concomitantly, spectral weight is transferred to higher energy r-space states that lack the characteristics of excitations from delocalized Cooper pairs. Instead, these states break translational and rotational symmetries locally at the atomic scale in an energy independent fashion. We demonstrate that these unusual r-space excitations are, in fact, the pseudogap states. Thus, as the Mott insulating state is approached by decreasing the hole density, the delocalized Cooper pairs vanish from k-space, to be replaced by locally translational- and rotational-symmetry-breaking pseudogap states in r-space.

This is author's version. See the Nature website for the published version

References in corpus (13)

• An Intrinsic Bond-Centered Electronic Glass with Unidirectional Domains in Underdoped Cuprates
• Evolution of the electronic excitation spectrum with strongly diminishing hole-density in superconducting Bi_{2}Sr_{2}CaCu_{2}O_{8+δ}
• Putting competing orders in their place near the Mott transition
• Theory of the nodal nematic quantum phase transition in superconductors
• Fourier transform spectroscopy of d-wave quasiparticles in the presence of atomic scale pairing disorder
• Nodal/Antinodal Dichotomy and the Two Gaps of a Superconducting Doped Mott Insulator
• Emergence of Cooper pairs, d-wave duality and the phase diagram of cuprate superconductors
• Superconducting d-wave stripes in cuprates: Valence bond order coexisting with nodal quasiparticles
• Competing orders II: the doped quantum dimer model
• Nodal quasiparticles and the onset of spin density wave order in the cuprates
• Electronic properties of disordered valence-bond stripes in cuprate superconductors
• Local quasiparticle lifetimes in a d-wave superconductor
• Fermi momentum resolved charge order for spin disordered stripes

Cited by in corpus (1)

• Electronic properties of disordered valence-bond stripes in cuprate superconductors