Doping and temperature dependence of electron spectrum and quasiparticle dispersion in doped bilayer cuprates

Abstract

Within the t-t ′ -J model, the electron spectrum and quasiparticle dispersion in doped bilayer cuprates in the normal state are discussed by considering the bilayer interaction. It is shown that the bilayer interaction splits the electron spectrum of doped bilayer cuprates into the bonding and antibonding components around the [π, 0] point. The differentiation between the bonding and antibonding components is essential, which leads to two main flat bands around the [π, 0] point below the Fermi energy. In analogy to the doped single layer cuprates, the lowest energy states in doped bilayer cuprates are located at the [π/2, π/2] point. Our results also show that the striking behavior of the electronic structure in doped bilayer cuprates is intriguingly related to the bilayer interaction together with strong coupling between the electron quasiparticles and collective magnetic excitations.

Electronic Structure of Kinetic Energy Driven Cuprate Superconductors

“…In corresponding to this weak dispersions in the superconducting state, the quasiparticle dispersions in the normal state exhibit the flat band around the [π, 0] point just below the Fermi energy [34,36]. Moreover, it is shown that the well pronounced peak-dip-hump structure [37] of the bilayer cuprate superconductors in the superconducting state and double-peak structure [36] in the normal state are mainly caused by the bilayer splitting. In particular, we show that one of the universal features is that the d-wave superconducting state in cuprate superconductors is the conventional BCS like, so that the basic BCS formalism with the d-wave symmetry is still valid in discussions of the low energy electronic structure of cuprate superconductors [32,33,35,37], although the pairing mechanism is driven by the kinetic energy by exchanging spin excitations, and other exotic magnetic properties [16,17,18] are beyond the BCS formalism.…”

“…Furthermore, the superconducting quasiparticles around the [π, 0] point disperse very weakly with momentum [35,37]. In corresponding to this weak dispersions in the superconducting state, the quasiparticle dispersions in the normal state exhibit the flat band around the [π, 0] point just below the Fermi energy [34,36]. Moreover, it is shown that the well pronounced peak-dip-hump structure [37] of the bilayer cuprate superconductors in the superconducting state and double-peak structure [36] in the normal state are mainly caused by the bilayer splitting.…”

“…In this paper, we give a brief review of our recent studies for the low energy electronic structure of the kinetic energy driven d-wave cuprate superconductors [32,33,34,35,36,37]. We show that in both superconducting and normal states, the spectral weight increases with increasing doping, and decreases with increasing temperatures [32,33,34,35,36,37]. Furthermore, the superconducting quasiparticles around the [π, 0] point disperse very weakly with momentum [35,37].…”

“…In particular, this superconducting state is the conventional BCS like with the d-wave symmetry, and is controlled by both superconducting gap function and quasiparticle coherence, then the maximal superconducting transition temperature occurs around the optimal doping, and decreases in both underdoped and overdoped regimes [31]. Within this framework of the kinetic energy driven superconductivity, we [32,33,34,35,36,37] have performed a systematic calculation for the low energy electron spectral function of the single layer and bilayer cuprate superconductors in both superconducting and normal states, and qualitatively reproduced all main features of the ARPES experimental measurements on the single layer and bilayer cuprate superconductors [4,5]. In this paper, we give a brief review of our recent studies for the low energy electronic structure of the kinetic energy driven d-wave cuprate superconductors [32,33,34,35,36,37].…”

“…Within this framework of the kinetic energy driven superconductivity, we [32,33,34,35,36,37] have performed a systematic calculation for the low energy electron spectral function of the single layer and bilayer cuprate superconductors in both superconducting and normal states, and qualitatively reproduced all main features of the ARPES experimental measurements on the single layer and bilayer cuprate superconductors [4,5]. In this paper, we give a brief review of our recent studies for the low energy electronic structure of the kinetic energy driven d-wave cuprate superconductors [32,33,34,35,36,37]. We show that in both superconducting and normal states, the spectral weight increases with increasing doping, and decreases with increasing temperatures [32,33,34,35,36,37].…”