Magnetic field induced quantum spin liquid in the two coupled trillium lattices of K$_2$Ni$_2$(SO$_4$)$_3$

TL;DR

This study reveals that applying a magnetic field to a three-dimensional network of interconnected Ni$^{2+}$ spins in K$_2$Ni$_2$(SO$_4$)$_3$ induces a quantum spin liquid state, highlighting the role of geometric frustration in such systems.

Contribution

The paper demonstrates that interconnected S=1 trillium lattices can host a magnetic field-induced quantum spin liquid state, advancing understanding of frustration in three-dimensional quantum magnets.

Findings

Magnetic field suppresses static order, revealing a quantum spin liquid state.

The system exhibits high geometric frustration due to interconnected trillium lattices.

Experimental evidence shows coexistence of dynamic and static magnetic components.

Abstract

Quantum spin liquids are exotic states of matter which form when strongly frustrated magnetic interactions induce a highly entangled quantum paramagnet far below the energy scale of the magnetic interactions. Three-dimensional cases are especially challenging due to the significant reduction of the influence of quantum fluctuations. Here, we report the magnetic characterization of {\kni} forming a three dimensional network of Ni$^{2+}$ spins. Using density functional theory calculations we show that this network consists of two interconnected spin-1 trillium lattices. In the absence of a magnetic field, magnetization, specific heat, neutron scattering and muon spin relaxation experiments demonstrate a highly correlated and dynamic state, coexisting with a peculiar, very small static component exhibiting a strongly renormalized moment. A magnetic field $B \gtrsim 4$ T diminishes the ordered component and drives the system in a pure quantum spin liquid state. This shows that a system of interconnected $S=1$ trillium lattices exhibit a significantly elevated level of geometrical frustration.