ES22-Adhikary

Presenter: Adhikary, Souren - Indian Institute of Science Education and Research Tirupati, India

Author: Sasmita Mohakud, Sudipta Dutta and Souren Adhikary. Department of Physics, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati - 517507, Andhra Pradesh, India.

Title: Antiferromagnetic spin ordering in two-dimensional honeycomb lattice of SiP3

Abstract: Magnetism in two-dimension has long been challenging, since the long-range spin-ordering can not sustain the thermal agitation due to vanishing spin-wave excitation gap, as described by Mermin-Wagner theory. Very recently there have been few reports of two-dimensional magnetism in transition metal tri-chalcogenide, halide and boride systems, that arises from uniaxial anisotropy of d-electrons, more specifically due to the spin-orbit-coupling. However, it has still been elusive for purely p-block elements unless introduced through defect engineering in carbon organic frame-works. Here we propose a purely two-dimensional buckled honeycomb-lattice of stoichiometry SiP3 that exhibits antiferromagnetic ground state with itinerant electrons, originating from Fermi-instability as a results of elemental Si substitution in pristine blue phosphorene to downshift the Fermi energy. The diverging density of states at Fermi energy, arising from hybrid bands and subsequent charge transfer from P to Si atoms due to the Lewis base character of P, stabilizes the system in a magnetic ground state. This group-IV - group-V binary system shows antiferromagnetically coupled tiny ferromagnetic triangular domains with magnetism arising from unhybridized π-electrons. Such metal-free and defect-free two-dimensional material can be exploited for spintronic and qubit applications and can tempt further theoretical and experimental explorations.