Eur. Phys. J. B 26, 67-74 (2002)
https://doi.org/10.1140/epjb/e20020067

Effect of strain-induced electronic topological transitions on the superconducting properties of La_2-xSr_xCuO₄ thin films

¹ Dipartimento di Fisica e Astronomia, Università di Catania, and Istituto Nazionale per la Fisica della Materia, UdR di Catania, Corso Italia, 57, 95129 Catania, Italy
² Dipartimento di Scienze e Tecnologie Fisiche ed Energetiche, Università di Roma “Tor Vergata”, Via di Tor Vergata, 110, 00133 Roma, Italy
³ Istituto Nazionale per la Fisica della Materia, UdR di Tor Vergata, Via di Tor Vergata, 110, 00133 Roma, Italy
⁴ Dipartimento di Matematica, Università di Torino, Via Carlo Alberto, 10, 10123 Torino, Italy
⁵ Dipartimento di Ingegneria Civile, Università di Roma “Tor Vergata”, Via di Tor Vergata, 110, 00133 Roma, Italy

Received: 1 October 2001
Revised: 5 December 2001
Published online: 15 March 2002

Abstract

We propose a Ginzburg-Landau phenomenological model for the dependence of the critical temperature on microscopic strain in tetragonal high-T_c cuprates. Such a model is in agreement with the experimental results for LSCO under epitaxial strain, as well as with the hydrostatic pressure dependence of T_c in most cuprates. In particular, a nonmonotonic dependence of T_c on hydrostatic pressure, as well as on in-plane or apical microstrain, is derived. From a microscopic point of view, such results can be understood as due to the proximity to an electronic topological transition (ETT). In the case of LSCO, we argue that such an ETT can be driven by a strain-induced modification of the band structure, at constant hole content, at variance with a doping-induced ETT, as is usually assumed.