Field-induced intertwined orders in 3D Mott-Kitaev honeycomb $\beta$-Li2IrO3

TL;DR

This paper investigates how small magnetic fields influence the frustrated quantum magnet $eta$-Li$_2$IrO$_3$, inducing intertwined orders without a true phase transition, revealing complex field-tuned magnetic behavior.

Contribution

It demonstrates that magnetic fields can manipulate frustrated magnetic states in $eta$-Li$_2$IrO$_3$, inducing intertwined orders without thermodynamic phase transitions.

Findings

Magnetic fields drive the system between different broken symmetry states.

No true thermodynamic phase transition occurs under small magnetic fields.

Field-induced states exhibit signatures of order parameters without true long-range order.

Abstract

Honeycomb iridates are thought to have strongly spin-anisotropic exchange interactions that could lead to an extraordinary state of matter known as the Kitaev quantum spin liquid. The realization of this state requires almost perfectly frustrated interactions between the magnetic Ir$^{4+}$ ions, but small imbalances in energy make other ordered states more favorable. Indeed, the closeness in energy of these ordered states is itself a signature of the intrinsic frustration in the system. In this work, we illustrate that small magnetic fields can be employed to drive the frustrated quantum magnet $\beta-$Li$_2$IrO$_3$,between different broken symmetry states, but without causing a true thermodynamic phase transition. This field-induced broken symmetry phase has all the signatures of a thermodynamic order parameter, but it is never truly formed in zero field. Rather, it is summoned when the scales of frustration are appropriately tipped, intertwined with other nearby quantum states.