Casamian, Paul (2024) Spin-Isospin Model of a Triangular Antiferromagnet. Bachelor's Thesis, Physics.
|
Text
bPHYS2024CasamianPPE.pdf Download (832kB) | Preview |
|
![[img]](https://fse.studenttheses.ub.rug.nl/style/images/fileicons/text.png) |
Text
toestemming.pdf Restricted to Registered users only Download (58kB) |
Abstract
Spin S = 1/2 triangular antiferromagnets are intriguing models that challenge our understanding of magnetic ordering. The variety of quantum phenomena they showcase, caused by their inherently frustrated geometry and quantum fluctuations, are of great interest due to their application in quantum computing, among others. Here, we discuss the triangular antiferromagnetic material Ba3TaFe3Si2O14, in which we replace the spin s = 5/2 iron ions, by spin s = 1/2 ions. This change results in the appearance of a new quantum degree of freedom, isospin. In the triangle chain, a one-dimensional model of triangles stacked along the c-axis, spins are in a disordered spin liquid state, whereas isospins show a short ranged helical spiral ordering. We then extend this model to three-dimensions by adding in-plane Heisenberg exchange interactions. It results in average spins to rotate along the c-axis, together with isospins. However, this rotation occurs in an arbitrary plane. The Dzyaloshinskii-Moriya interaction is responsible for the spins and isospins rotation axes to align, either parallel or anti-parallel. This thesis opens the door for investigations that go beyond the mean field approximation and account for quantum spin and isospin fluctuations in the ground state.
| Item Type: | Thesis (Bachelor's Thesis) |
|---|---|
| Supervisor name: | Mostovoy, M.V. |
| Degree programme: | Physics |
| Thesis type: | Bachelor's Thesis |
| Language: | English |
| Date Deposited: | 23 Jul 2024 10:48 |
| Last Modified: | 23 Jul 2024 10:48 |
| URI: | https://fse.studenttheses.ub.rug.nl/id/eprint/33585 |
Actions (login required)
 |
View Item |