Projected SO(5) Hamiltonian for Cuprates and Its Applications

Дата и время публикации : 2000-09-27T09:28:15Z

Авторы публикации и институты :
Assa Auerbach (Technion and ITP, UCSB)
Ehud Altman (Technion and ITP, UCSB)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 3 EPS figures
Первичная категория: cond-mat.str-el

Все категории : cond-mat.str-el, cond-mat.supr-con

Краткий обзор статьи: The projected SO(5) (pSO(5)) Hamiltonian incorporates the quantum spin and superconducting fluctuations of underdoped cuprates in terms of four bosons moving on a coarse grained lattice. A simple mean field approximation can explain some key feautures of the experimental phase diagram: (i) The Mott transition between antiferromagnet and superconductor, (ii) The increase of T_c and superfluid stiffness with hole concentration x and (iii) The increase of antiferromagnetic resonance energy as sqrt{x-x_c} in the superconducting phase. We apply this theory to explain the “two gaps” problem found in underdoped cuprate Superconductor-Normal- Superconductor junctions. In particular we explain the sharp subgap Andreev peaks of the differential resistance, as signatures of the antiferromagnetic resonance (the magnon mass gap). A critical test of this theory is proposed. The tunneling charge, as measured by shot noise, should change by increments of Delta Q= 2e at the Andreev peaks, rather than by Delta Q=e as in conventional superconductors.

Category: Physics