FIZIKA A 8 (1999) 4 , 311-318

QUANTUM PHASE TRANSITION IN A RANDOM-TILING MODEL

DENIS K. SUNKO

Department of Physics, Faculty of Science, University of Zagreb, Bijenčka cesta 32, HR-10000 Zagreb, Croatia,    

E-mail: dks@phy.hr

Dedicated to Professor Boran Leontić on the occasion of his 70^th birthday

Received 23 November 1999; Accepted 17 April 2000

The analogue of a Mott-Hubbard transition is discussed, which appears at an incommensurate filling in a model of a two-dimensional plane, randomly tiled with CuO₄ `molecules', simulating the copper-oxide planes of high-T_c superconductors. It is shown to be a quantum phase transition, which can be crossed either in doping, at a fixed hopping overlap t, or in t, when the doping is fixed in a certain range below half-filling. It is first-order, closely analogous to a liquid-gas transition.

PACS numbers: 74.20.-z
UDC 538.945

Keywords: Mott-Hubbard transition, high-T_c superconductivity

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