Probing and controlling magnetic ground states in van der Waals antiferromagnet CrSBr
Wednesday 05 February 2025, 12:01pm
Dr. Amit Sharad Pawbake, Laboratoire National des Champs Magnétique Intenses, CNRS
Location : AB2-5B
Abstract: Magnetic excitations in an air-stable layered magnetic material CrSBr,
that can be thinned down to the two-dimensional (2D) monolayer limit,
are of high interest from a fundamental point of view and for
applications perspectives [1-2]. In this work, we investigate the
magnetization process of a biaxial antiferromagnet CrSBr in an
external magnetic field applied along the easy axis and study the
elementary excitations.
We performed a microwave absorption study of the low-energy magnon
excitations in bulk CrSBr. The magnetic-field dependence of two
resonance modes is measured up to well above the saturation fields,
revealing anisotropies, magnetic transitions, and a strong
magnon-magnon coupling in this material [3]. Magneto-Raman scattering
spectroscopy unveils robust spin-lattice coupling, evident in the
emergence of new zone folded phonon modes when the additional magnetic
periodicity develops below TN and by pronounced variations of the
scattered intensity [4].
Further, with hydrostatic pressure, we modify the competition between
exchange interactions and magnetocrystalline anisotropy. We find that
the single meta-magnetic transition of the Ising type observed in this
material under ambient pressure transforms under hydrostatic pressure
into two transitions, a first-order spin-flop transition followed by a
second-order transition toward a polarized ferromagnetic state near
saturation. This reversible tuning into a new magnetic phase is
obtained in layered bulk CrSBr at low temperature by varying the
interlayer distance using high hydrostatic pressure, which efficiently
acts on the interlayer magnetic exchange and is probed by
magneto-optical spectroscopy [5].
References:
[1] E. Telford et.al, Adv. Mater. 32, 2003240 (2020)
[2] N. Wilson et.al, Nat. Mater. 20, 1657 (2021)
[3] C. Cho et.al, Phys. Rev. B 107, 094403 (2023)
[4] A. Pawbake et.al, Phys. Rev. B. 107, 075421 (2023)
[5] A. Pawbake et.al, Nano Lett. 23, 9587 (2023)