Hole pairing from attraction of opposite-chirality spin vortices: Non-BCS superconductivity in underdoped cuprates

Marchetti, P. A.1; Ye, F.2; Su, Z. B.3; Yu, L.3,4,5

2011-12-27

10.1103/PhysRevB.84.214525

PHYSICAL REVIEW B   Impact Factor & Quartile

2469-9950

2469-9969

Within a gauge approach to the t - J model, we propose a non-BCS mechanism of superconductivity (SC) for underdoped cuprates. We implement the no-double-occupancy constraint with a (semionic) slave-particle formalism. The dopant in the t - J model description generates a vortexlike quantum distortion of the antiferromagnetic (AF) background centered on the empty sites, with opposite chirality for cores on the two Neel sublattices. Empty sites are described in terms of spinless fermionic holons and the long-range attraction between spin vortices on two opposite Neel sublattices serves as the holon pairing force, leading eventually to SC. The spin fluctuations are described by bosonic spinons with a gap generated by scattering on spin vortices. Due to the no-double occupation constraint, there is a gauge attraction between holon and spinon, binding them into a physical hole. Through gauge interaction the spin-vortex attraction induces the formation of spin-singlet [resonance valence bond (RVB)] spin pairs by lowering the spinon gap, due to the appearance of spin-vortex dipoles. Lowering the temperature, the proposed approach anticipates two crossover temperatures as precursors of the SC transition: at the higher crossover a finite density of incoherent holon pairs are formed, leading to reduction of the hole spectral weight, while at the lower crossover a finite density of incoherent spinon RVB pairs is also formed, giving rise to a gas of incoherent preformed hole pairs with magnetic vortices appearing in the plasma phase, supporting a Nernst signal. Finally, at an even lower temperature the hole pairs become coherent, the magnetic vortices become dilute, and SC appears beyond a critical doping. The proposed SC mechanism is not of the BCS type, because it involves a gain in kinetic energy, due to the lowering of the spinon gap, and it is "almost" of the classical three-dimensional XY type. Since both the spinon gap describing short-range antiferromagnetism order, and the holon pairing generating SC, originate from the same term in the slave-particle representation of the t - J model, the proposed approach incorporates a strong interplay between antiferromagnetism and SC, giving rise to a universal relation between T-c and the energy of the resonance mode, as observed in neutron-scattering experiments.

SCI ; EI

English

NI Journal Papers

Others

NSFC[10904081]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter

WOS:000298551500010

AMER PHYSICAL SOC

PHYSICS

Web of Science

1.Ist Nazl Fis Nucl, Dipartimento Fis, I-35131 Padua, Italy
2.S Univ Sci & Technol China, Dept Phys, Shenzhen 518055, Peoples R China
3.Chinese Acad Sci, Inst Theoret Phys, Beijing 100190, Peoples R China
4.Chinese Acad Sci, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China
5.Chinese Acad Sci, Inst Phys, Beijing 100190, Peoples R China

Marchetti, P. A.,Ye, F.,Su, Z. B.,et al. Hole pairing from attraction of opposite-chirality spin vortices: Non-BCS superconductivity in underdoped cuprates[J]. PHYSICAL REVIEW B,2011,84(21).

Marchetti, P. A.,Ye, F.,Su, Z. B.,&Yu, L..(2011).Hole pairing from attraction of opposite-chirality spin vortices: Non-BCS superconductivity in underdoped cuprates.PHYSICAL REVIEW B,84(21).

Marchetti, P. A.,et al."Hole pairing from attraction of opposite-chirality spin vortices: Non-BCS superconductivity in underdoped cuprates".PHYSICAL REVIEW B 84.21(2011).