Charge density wave and Weyl Semimetal phase in Y${}_2$Ir${}_2$O${}_7$

Abstract

The subtle interplay of band topology and symmetry broken phase, induced by electron correlations, has immense contemporary relevance and potentially offers novel physical insights. Here, we demonstrate charge density wave (CDW) in bulk Y${}_2$Ir${}_2$O${}_7$ for T < 10 K, and its transition to the Weyl semimetal (WSM) phase at higher temperatures. The CDW phase is evidenced by a) current induced nonlinear conductivity with negative differential resistance at low temperature, b) low frequency Debye like dielectric relaxation at low temperature with a large dielectric constant, and c) an anomaly in the temperature dependence of the thermal expansion coefficient. The WSM phase at higher temperature is confirmed by the DC and AC transport measurements which show an inductive response at low frequencies. More interestingly, we show that by reducing the crystallite size, the low temperature CDW phase can be eliminated leading to the restoration of the WSM phase.

5 pages, 4 figures; minor corrections

References in corpus (8)

• Novel Jeff = 1/2 Mott State Induced by Relativistic Spin-Orbit Coupling in Sr2IrO4
• Chiral anomaly, Charge Density Waves, and Axion Strings from Weyl Semimetals
• Magnetic Order in the Pyrochlore Iridates A2Ir2O7 (A = Y, Yb)
• Topological charge density waves at half-integer filling of a moiré superlattice
• Evolution of structure, magnetism and electronic transport in doped pyrochlore iridate Y${}_2$Ir${}_{2-x}$Ru${}_x$O${}_7$
• Colossal enhancement of electrical conductivity in Y2Ir2O7 nanoparticles
• Unified description of resistivity and thermopower of Pr${}_2$Ir${}_2$O${}_7$: possible influence of crystal field excitation in a Kondo lattice
• Non-Fermi liquid regime in metallic pyrochlore iridates: Quantum Griffiths singularities

Cited by in corpus (1)

• Identification of Griffiths-like phase and its evolution in Cr substituted pyrochlore iridates $Y_{2}I{r}_2{O}_7$