Polaronic metal in lightly doped high-T_c cuprates

¹ Cross-Correlated Materials Research Group (CMRG), ASI, RIKEN - Wako 351-0198, Japan
² RRC “Kurchatov Institute” - 123182, Moscow, Russia
³ Department of Applied Physics, The University of Tokyo - 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan
⁴ Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University - Ithaca, NY 14853, USA
⁵ Department of Physics, Applied Physics, and Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory - Menlo Park, CA 94025, USA
⁶ Stanford University - Stanford, CA 94305, USA
⁷ National Lab for Superconductivity, Institute of Physics, Chinese Academy of Sciences - Beijing 100190, China

^a mishchenko@riken.jp

Received: 7 April 2011
Accepted: 20 July 2011

Abstract

We present a combined study of the angle-resolved-photoemission spectroscopy (ARPES) and quantum Monte Carlo simulations to propose a novel polaronic metallic state in underdoped cuprates. An approximation scheme is proposed to represent underdoped cuprates away from 1/2 filling, replacing the many-body Hamiltonian by that of a single polaron with effective electron-phonon interaction (EPI), that successfully explains many puzzles such as a large momentum-dependent dichotomy between nodal and antinodal directions, and an unconventional doping dependence of ARPES in the underdoped region.