2002/09/04 by P. Wrobel, P Wr bel, R. Eder +1 · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Bipolaron #Condensed matter physics #Cuprate #Doping #Electron #Hamiltonian (control theory) #Kinetic energy #Magnetic and transport properties of perovskites and related materials #Physics #Physics of Superconductivity and Magnetism #Polaron #Pseudogap #Quantum mechanics #Superconductivity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1088/0953-8984/15/17/326
14 pages, 4 figures
arxiv created 2002/09/04 · openalex publication_date 2003/04/22 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
By analysing an effective Hamiltonian for spin polarons forming in weakly doped antiferromagnets represented by the t – J model we demonstrate that the driving mechanism which gives rise to superconductivity in such a system is the lowering of the kinetic energy, which is consistent with recent experimental observations. That source of attraction between holes is effective if the antiferromagnetic correlation length is longer than the radius of polarons. Notwithstanding that the attraction is strongest in the undoped system with long-range order, the superconducting order parameter vanishes when the doping parameter decreases, which can be attributed to emptying the spin polaron band and approaching the Mott insulator phase. Since the hypothetical normal phase of a low-density gas of fermions is unstable against formation of bound hole pairs the intensity of low-energy excitations is suppressed and a pseudogap forms in the underdoped region.