Advanced search
Start date
Betweenand
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Quantum criticality in a layered iridate

Full text
Author(s):
Samanta, Kousik [1] ; Souza, Jean C. [1] ; Rigitano, Danilo [1] ; Morales, Adimir I. [1] ; Pagliuso, Pascoal G. [1] ; Granado, Eduardo [1]
Total Authors: 6
Affiliation:
[1] Univ Campinas UNICAMP, Gleb Wataghin Inst Phys, Campinas, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: COMMUNICATIONS PHYSICS; v. 4, n. 1 MAY 10 2021.
Web of Science Citations: 0
Abstract

Iridates provide a fertile ground to investigate correlated electrons in the presence of strong spin-orbit coupling. Bringing these systems to the proximity of a metal-insulator quantum phase transition is a challenge that must be met to access quantum critical fluctuations with charge and spin-orbital degrees of freedom. Here, electrical transport and Raman scattering measurements provide evidence that a metal-insulator quantum critical point is effectively reached in 5% Co-doped Sr2IrO4 with high structural quality. The dc-electrical conductivity shows a linear temperature dependence that is successfully captured by a model involving a Co acceptor level at the Fermi energy that becomes gradually populated at finite temperatures, creating thermally-activated holes in the J(eff)=1/2 lower Hubbard band. The so-formed quantum critical fluctuations are exceptionally heavy and the resulting electronic continuum couples with an optical phonon at all temperatures. The magnetic order and pseudospin-phonon coupling are preserved under the Co doping. This work brings quantum phase transitions, iridates and heavy-fermion physics to the same arena. Due to a combination of strong spin orbit coupling and electron correlations iridates such as Sr2IrO4 exhibit a range of exotic quantum states that can be tuned via their electronic and magnetic properties. Here, the authors investigate the resistive and Raman scattering properties of Co-doped Sr2IrO4 and provide evidence for quantum critical fluctuations in the system. (AU)

FAPESP's process: 18/11364-7 - Magnetic properties of complex systems with non-trivial topology
Grantee:Jean Carlo Souza
Support type: Scholarships in Brazil - Doctorate
FAPESP's process: 18/18653-4 - Search for emergent electronic states in the two-dimensional Iridates (Sr1-xAx)2IrO4 (A=Ca, BA)
Grantee:Adimir Italo Vilca Morales
Support type: Scholarships in Brazil - Master
FAPESP's process: 17/10581-1 - Emergent phenomena in reduced dimension systems
Grantee:Pascoal Jose Giglio Pagliuso
Support type: Research Projects - Thematic Grants
FAPESP's process: 16/00756-6 - Synthesis and Fundamental Investigation of Novel Correlated Electron Systems with Strong Spin-orbit Coupling
Grantee:Kousik Samanta
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 18/20142-8 - Vibrational dynamics, spin waves and orbital excitations in transition-metal oxides
Grantee:Eduardo Granado Monteiro da Silva
Support type: Regular Research Grants