Reentrant incommensurate order and anomalous magnetic torque in the Kitaev magnet β-Li2IrO3
Abstract
We present a theoretical study of the response of β-Li2IrO3 under external magnetic fields in the ab, bc and ac crystallographic planes. The results are based on the minimal nearest-neighbor J-K- model and reveal a rich intertwining of field-induced phases and magnetic phase transitions with distinctive signatures that can be probed directly via torque magnetometry. Most saliently, we observe: i) an unusual reentrance of the incommensurate counter-rotating order for fields in the ab-plane, and ii) a set of abrupt torque discontinuities which are particularly large for fields rotating in the bc plane, and whose characteristic shape resembles closely the ones observed in the 3D Kitaev magnet γ-Li2IrO3. An experimental confirmation of these predictions will pave the way for an accurate determination of all relevant microscopic parameters of this 3D Kitaev magnet.