Lattice vibrations of alpha'-NaV_2O_5 in the low-temperature phase. Magnetic bound states?

Abstract

We report high resolution polarized infrared studies of the quarter-filled spin ladder compound alpha'-NaV_2O_5 as a function of temperature (5K <= T <= 300K). Numerous new modes were detected below the temperature T_c=34K of the phase transition into a charge ordered nonmagnetic state accompanied by a lattice dimerization. We analyse the Brillouin zone (BZ) folding due to lattice dimerization at T_c and show that some peculiarities of the low-temperature vibrational spectrum come from quadruplets folded from the BZ point (1/2, 1/2, 1/4). We discuss an earlier interpretation of the 70, 107, and 133cm-1 modes as magnetic bound states and propose the alternative interpretation as folded phonon modes strongly interacting with charge and spin excitations.

arXiv comment15 pages, 13 Postscript figures

References in corpus (26)

• NaV_2O_5 as a quarter-filled ladder compound
• Experimental evidence for a spin-Peierls-transition in ${\alpha }^{\prime }-Na{V}_2{O}_5$
• A new view of the electronic structure of the spin-Peierls compound alpha'-NaV2O5
• Charged Magnons in NaV2O5
• Charge ordering and opening of spin gap in NaV_2O_5
• X-ray Anomalous Scattering Study of a Charge-Ordered State in NaV2O5
• Raman, infrared and optical spectra of the spin-Peierls compound NaV_2O_5
• Interference of a first-order transition with the formation of a spin-Peierls state in alpha'-NaV2O5?
• Response: Spin-Singlet clusters in the ladder compound NaV2O5
• Spin gap behavior and charge ordering in α^{\prime}-NaV_2O_5 probed by light scattering
• Magnetic bound states in the quarter-filled ladder system ${\alpha }^{\prime }-Na{V}_2{O}_5$}
• Optical spectroscopic study of the interplay of spin and charge in NaV2O5
• Elastic Constants and Charge Ordering in a'-NaV2O5
• Electron-phonon and spin-phonon coupling in NaV${}_2$O${}_5$: charge fluctuations effect
• Study of spin-Peierls transition in alpha'--NaV2O5 by infrared reflectivity
• Structure determination, valence, and superexchange in the dimerized low temperature phase of alpha'-NaV2O5
• Charge Ordering and Spin Dynamics in NaV2O5
• Zigzag Charge Ordering in alpha'-NaV2O5
• Raman Scattering in the Inorganic Spin-Peierls System alpha'-Na_{1-delta}V_2O_5
• Appearance of new lines and change in line shape in the IR spectrum of a NaV_2O_5 single crystal at the spin-Peierls transition
• Lattice vibrations of alpha'-NaV2O5
• High frequency ESR investigation on dynamical charge disproportionation and spin gap excitation in NaV_2O_5
• First evidence for charge ordering in NaV${}_2$O${}_5$ from Raman spectroscopy
• Low-energy excitations in NaV2O5
• Infrared study of spin-Peierls compound alpha'-NaV2O5
• Dzyaloshinskii-Moriya interaction in NaV${}_2$O${}_5$: a microscopic study

Cited by in corpus (8)

• Magnetic light scattering in low-dimensional quantum spin systems
• Probing spin correlations with phonons in the strongly frustrated magnet ZnCr2O4
• Low energy excitations and dynamic Dzyaloshinskii-Moriya interaction in ${\alpha }^{\prime }$-NaV${}_2$O${}_5$ studied by far infrared spectroscopy
• Optical properties, electron-phonon coupling, and Raman scattering of vanadium ladder compounds
• Single-particle spectral function of quarter-filled ladder systems
• Charge ordering in quarter-filled ladder systems coupled to the lattice
• Electronic Properties of α'-NaV_2O_5
• Terahertz light driven coherent excitation of a zone-folded Raman-active phonon mode in the Spin-Ladder System ${\alpha }^{\prime }$-NaV${}_2$O${}_5$