Abstract
Molecules have been studied since the beginning of the 21st century as a potential alternative to traditional silicon-based devices. The small size of a molecule can result in faster performance. There have been many single-molecule devices developed, such as molecular diodes, molecular memories, molecular wires, molecular field-effect transistors (FETs), and molecular switches. Ideally, one can control the behavior of an electron in a molecule and perform specific functions on it. Such a device would have very low power consumption and heat generation [1]. Electron spin, as a candidate for a qubit, offers some advantages over other types of qubits, such as the ability to be placed in a superposition state with a pulsed microwave [2].Rare-earth elements possess interesting magnetic properties that make them a viable option for emerging quantum technologies, including quantum transduction and quantum memories. Er3+ has a long spin coherence time, and its electrons are optically accessible. Er2O3 is a non-collinear antiferromagnetic material at low temperatures. We model its crystal field using Stevens operators, which yields the same energy splitting and g-factor. Then, we use that to model magnon energy. We consider magnons that are governed by the exchange interaction, magnetic dipolar interaction, and a small external magnetic field. The Holstein-Primakoff representation and para-unitary diagonalization are employed to quantize the effective spin Hamiltonian. The long-range nature of the magnetic dipolar interaction makes it the dominant factor for magnons with long wavelengths and introduces a magnonic band gap at the �� point.