Magnon and Soliton Excitations in the Carrier-Poor, One-Dimensional S=1/2 Antiferromagnet Yb₄As₃

Staggered Field Effect on the One-DimensionalS=12AntiferromagnetYb4Kohgi1, Iwasa2, Mignot3 et al. 2001Phys. Rev. Lett.1307691View full textAdd to dashboardCite

“…There is, however, another puzzling fact concerning the thermal properties of Yb 4 As 3 under magnetic field: the specific heat exhibits strong suppression at low temperatures and a broad hump around temperatures which increase with increasing magnetic field [7]; thermal expansion shows also a corresponding anomaly [8,9]. This fact suggests that a gap is opened in the low energy excitations of Yb 4 As 3 under magnetic field, being in contradiction to the 1D-HAF model where magnetic fields do not open any energy gap in the density of state.…”

Low-energy excitations of the semimetallic one-dimensional S=1/2 antiferromagnet Yb4As3

“…These solutions, usually called solitons, are described by their mass, m s ; and their rest energy, E s : As discussed in Refs. [45,47], excellent fits are achieved if one allows for m s ðBÞ; E s ðBÞ; and a third adjustable parameter, i.e., the spin gap in the magnon spectrum, DðBÞ; and a soliton-derived Gr .…”

Field-Dependent Specific Heat and Energy Gap in the Yb4As3Compound

“…The full symbols represent numerical results. The open symbols represent the experimental data [7] collected for B = 6 T after subtraction of the phonon contribution (2). The (969)…”

“…On the basis of experimental data published in [7] and results of the present simulations, needed to extract the part corresponding to the perpendicular field direction, the experimental value of ∆ is estimated for the magnetic field of B = 6 T. Figure 2 presents the gap dependence on the magnetic field obtained on the basis of inelastic neutron scattering (INS) measurements (full circles) and that obtained from the specific heat measurements which is plotted by full squares and an open square. The former are taken from [6] and the latter is calculated here.…”

“…Such data, performed on different sample and experimental setup, are present in Ref. [7]. Here we select the representative cases B = 0 and B = 6 T. The latter is also attractive, because it corresponds to B eff ≤ 3.2 T and may shift the lower bound of the range of the experimental verification of the gap scaling which is not trivial to achieve.…”