Magnetic Raman scattering in S = 1/2 two-leg ladder compound NaV_2O_5
Abstract
We present results on magnetic Raman scattering at T = 300 K from NaV_2O_5, a quarter-filled two-leg ladder compound which can be mapped onto a S = 1/2 antiferromagnetic linear chain with frustration. The multispinon continuum peaked around 80 meV is present in parallel polarization along and perpendicular to the ladder direction and absent in cross polarization. We estimate a value J ~ 28 meV for the superexchange integral. The coupling to light of the magnetic excitations increases by orders of magnitude when the incoming photon frequency is close to the interband transitions observed in optical absorption. This is due to the resonant enhancement of the photon induced spin exchange process. We qualitatively discuss these results in comparison with two-magnon scattering from gapfull quasi one-dimensional two-leg ladders Sr_14Cu_24O_41 at half filling.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2002
- Bibcode:
- 2002APS..MARM16002G