| title: | Singlet-triplet transitions in terahertz spectra of spin-gap materials |
|---|---|
| reg no: | ETF6138 |
| project type: | Estonian Science Foundation research grant |
| status: | accepted |
| institution: | Institute of Chemical Physics and Biophysics |
| head of project: | Urmas Nagel |
| duration: | 01.01.2005 - 31.12.2008 |
| description: | The aim of the project is to study the mechanisms of optical singlet to triplet transitions in low-dimensional spin gap materials. The question to answer is whether the dynamic Dzyaloshinskii-Moriya mechanism which is based on spin-phonon interaction and allows optical singlet to triplet transitions in a'-NaV2O5 and SrCu2(BO3)2, is universal and works in other spin gap materials as well. We plan to measure how the selection rules of optical transitions depend on the applied magnetic field, polarization, and temperature in low-dimensional materials with a singlet ground state. The selected materials include Na5RbCu4(AsO4)4Cl2, TlCuCl3, BaCuSiO6, Sr14Cu24O41, etc. We plan to measure infrared spectra in the range from 0.09 to 7.5 THz in NICPB using a superconducting magnet with the maximum field 12 T. Higher fields up to 45 T are accessible at the National High Magnetic Laboratory in Tallahassee, Florida. Low-dimensional spin systems have proven to be useful models to study quantum many particle systems where far-infrared spectroscopy can provide unique information. |
| project group | ||||
|---|---|---|---|---|
| no | name | institution | position | |
| 1. | Dan Hüvonen | Institute of Chemical Physics and Biophysics | research scientist | |
| 2. | Urmas Nagel | Institute of Chemical Physics and Biophysics | senior research scientist | |
| 3. | Toomas Rõõm | Institute of Chemical Physics and Biophysics | senior research scientist | |