Griffiths-like phase close to the Mott transition

Author(s)

Mello, Isys F. ^[1] ; Squillante, Lucas ^[1] ; Gomes, Gabriel O. ^[2] ; Seridonio, Antonio C. ^[3] ; de Souza, Mariano ^[1]

Affiliation

^[1] Sao Paulo State Univ Unesp, IGCE Phys Dept, BR-13506900 Rio Claro, SP - Brazil

^[2] Univ Sao Paulo, Dept Astron, BR-05508090 Sao Paulo - Brazil

^[3] Sao Paulo State Univ UNESP, Dept Phys & Chem, BR-15385000 Ilha Solteira, SP - Brazil

• Document type: Journal article
• Source: Journal of Applied Physics; v. 128, n. 22 DEC 14 2020.
• Web of Science Citations: 0

Abstract

We explore the coexistence region in the vicinity of the Mott critical end point employing a compressible cell spin- 1 / 2 Ising-like model. We analyze the case for the spin-liquid candidate kappa-(BEDT-TTF) 2Cu 2(CN) 3, where close to the Mott critical end point metallic puddles coexist with an insulating ferroelectric phase. Our results are fourfold: (i) a universal divergent-like behavior of the Gruneisen parameter upon crossing the first-order transition line; (ii) based on scaling arguments, we show that within the coexistence region, for any system close to the critical point, the relaxation-time is entropy-dependent; (iii) we propose the electric Gruneisen parameter Gamma E, which quantifies the electrocaloric effect; and (iv) we identify the metallic/insulating coexistence region as an electronic Griffiths-like phase. Our findings suggest that Gamma E governs the dielectric response close to the critical point and that an electronic Griffiths-like phase emerges in the coexistence region. (AU)

• FAPESP's process: 11/22050-4 - Exploring thermodynamic and transport properties of strongly correlated electron systems
• Grantee: Valdeci Pereira Mariano de Souza
• Support Opportunities: Regular Research Grants