Unusual “Spin Liquid” Quantum State Found in TbInO3

Published August 19, 2019

Schematic of TbInO3 in which one electron sits at each site on a triangular lattice

Using intense pulsed magnetic fields and measurements at low temperatures, MagLab users have found evidence of a long-sought “spin liquid” in terbium indium oxide (TbInO₃)

What did scientists discover?

Using intense pulsed magnetic fields and measurements at low temperatures, MagLab users have found evidence of a long-sought “spin liquid” in terbium indium oxide: TbInO3. In this material, the magnetic fields of the electrons (the “spins”) have a strong tendency to want to align in opposite directions with their neighbors (called “antiferromagnetism”) but they are “frustrated”. That is because three spins on a triangle cannot anti-align with each of their two neighbors. In TbInO3, the frustrated spins instead form an unusual dynamic quantum state called a “spin liquid”. This material is unique in that it also has clean and atomically-thin grain boundaries between the spin liquid regions that can create a special state of spins coming from the edges rather than the center of the spin liquid regions.

Why is this important?

Physicists have long been seeking a material in which an elusive spin liquid state can be observed. In a spin liquid, the electrons do not move, so spin liquids are electrical insulators. However, the magnetic field orientations of the electrons, their so-called "spins", do move, behaving like a liquid of spins. As such, a spin liquid is a new form of quantum state that goes beyond ordinary static ordering of spins.

In this material, clean and atomically thin edges between spin liquid regions can host so-called "Majorana fermions", which are elusive particles that could be used for quantum computing.

Who did the research?

Jaewook Kim¹, Xueyun Wang¹, Fei-Ting Huang¹, Yazhong Wang¹, Xiaochen Fang¹, Xuan Luo², Y.Li^1,3, Meixia Wu^1,4, S.Mori⁵, D.Kwok¹, Eun Deok Mun^6,7, V.S. Zapf⁶, and Sang-Wook Cheong^1,2

¹Rutgers Univ; ²Max Plank POSTECH, Pohang Univ of Science and Technology; ³Shandong Univ; ⁴South China Univ of Technology, ⁵Osaka Prefecture Univ; ⁶National Maglab-Pulsed Field Facility, LANL; ⁷Simon Fraser Univ, Canada

Why did they need the MagLab?

The magnetic properties needed to be measured up to 60T to rule out magnetic ordering, to identify the crystal electric field levels to determine the magnetic state of the Tb atoms, and to fit the data to relevant theoretical models.