Spin-Polaron approach to the Fermi surface evolution in the normal state of cuprates.pdfVIP

Spin-Polaron approach to the Fermi surface evolution in the normal state of cuprates ∗ + ∗ ∗ ∗ A.F.Barabanov , R.Hayn , A.A.Kovalev , O.V.Urazaev , and A.M.Belemouk ∗Institute for High Pressure Physics, 142190 Troitsk, Moscow region, Russia 0 +Institute for Solid State and Materials Research (IFW), 0 0 P.O. Box 270016, D-01171 Dresden, Germany 2 p () e A semi-phenomenological approach to describe the evolution of Fermi S surface (FS) and electronic structure with doping is presented which is based 5 1 on the spin-fermion model. The doping is simulated by a frustration term in the spin Hamiltonian and the complex internal structure of the spin-polaron ] l quasiparticle is taken into account by a superposition of spin-polaron states e - with different radii. By calculating the spectrum, the spectral weights and r t the FS we find a rather drastic change of the electronic structure with s t. doping which explains many photoemission data, i.e. the isotropic band a bottom and the remnant FS of undoped cuprates, the large FS and the m extended saddle point of optimally doped compounds and the pseudogap - d in the underdoped samples. n PACS number(s): 75.50.Ee, 74.20.Mn, 71.38.+i, 75.30.Mb o c [ 1 v I. INTRODUCTION 7 3 The evolution of Fermi surface (FS) and electronic spectrum in the normal state of high 2 9 temperature superconductors are intensiv