Biomedical subjects

T Ziman

Publications and source records attributed to T Ziman.

15 recordsLinked to original sources

PubMed2004

Ordering and excitations in the field-induced magnetic phase of Cs3Cr2Br9.

Field-induced magnetic order has been investigated in detail in the interacting spin 3/2 dimer system Cs3Cr2Br9. Elastic and inelastic neutron scattering measurements were performed up to H=6 T, well above the critical field H(c1) approximately 1.5 T. The ordering displays incommensurabilities and a large hysteresis before a commensurate structure is reached. This structure is fully determined. Surprisingly, the lowest excitation branch never closes. Above H(c1), the gap increases slowly with the field. An analysis in terms of projected pseudospins is given.

Journal Article↗

PubMed2003

Exact soliton solution and inelastic two-soliton collision in a spin chain driven by a time-dependent magnetic field.

We investigate dynamics of exact N-soliton trains in a spin chain driven by a time-dependent magnetic field by means of an inverse scattering transformation. The one-soliton solution indicates obviously the spin precession around the magnetic field and periodic shape variation induced by the time-varying field as well. In terms of the general soliton solutions, N-soliton interaction and particularly various two-soliton collisions are analyzed. The inelastic collision by which we mean the soliton shape change before and after collision appears is generally due to the time-varying field. We, moreover, show that complete inelastic collisions can be achieved by adjusting spectrum and field parameters. This may lead to a potential technique of shape control of soliton.

Journal Article↗

PubMed2001

Dzyaloshinski-Moriya interaction in the 2D spin gap system SrCu(2)(BO(3))(2).

The Dzyaloshinski-Moriya interaction partially lifts the magnetic frustration of the spin-1/2 oxide SrCu(2)(BO(3))(2). It explains the fine structure of the excited triplet state and its unusual magnetic field dependence, as observed in previous ESR and new neutron inelastic scattering experiments. We claim that it is mainly responsible for the dispersion. We propose also a new mechanism for the observed ESR transitions forbidden by standard selection rules, which relies on an instantaneous Dzyaloshinski-Moriya interaction induced by spin-phonon couplings.

Journal Article↗

PubMed2001

Charge ordering and spin dynamics in NaV(2)O(5).

We report high-resolution neutron inelastic scattering experiments on the spin excitations of NaV(2)O(5). Below T(c), two branches with distinct energy gaps are identified. From the dispersion and intensity of the spin excitation modes, we deduce the precise zigzag charge distribution on the ladder rungs and the corresponding charge order: Delta(c) approximately 0.6. We argue that the spin gaps observed in the low-T phase of this compound are primarily due to the charge transfer.

Journal Article↗

PubMed1996