110 citations · 859 across the 63 of their papers we have counts for
5 papers · 1 filter
Phase Diagram of Bond-Alternating XXZ chains
Atsuhiro Kitazawa, Kiyohide Nomura, Kiyomi Okamoto
The phase transitions between the XY, the dimer and the Haldane phases of the spin-1 bond-alternating XXZ chain are studied by the numerical diagonalization. We determine the phase…
Critical Properties of the transition between the Haldane phase and the large-D phase of the spin-1/2 ferromagnetic-antiferromagnetic Heisenberg chain with on-site anisotropy"
Kiyomi Okamoto
We analytically study the ground-state quantum phase transition between the Haldane phase and the large- (LD) phase of the ferromagnetic-antiferromagnetic alternating He…
Dimer Correlarions in Spin-1/2 Alternating XY Chain
Yohei Saika, Kiyomi Okamoto
We investigate the long-distance asymptotic behavior of the dimer correlations in the spin-1/2 alternating chain both at T=0 and at sufficiently low-temperatures. The correlati…
Plateau of the Magnetization Curve of the S=1/2 Ferromagnetic-Ferromagnetic-Antiferromagnetic Spin Chain
Kiyomi Okamoto
I analytically study the plateau of the magnetization curve at (where is the saturation magnetization) of the one-dimensional trimerized Hei…
Critical Properties of the XXZ chain in External Staggered Magnetic Field
Kiyomi Okamoto, Kiyohide Nomura
We comment on the recent work of Alcaraz and Malvezzi [1995 {\it J. Phys. A: Math. Gen.} {\bf 19} 1521] for the critical properties of the chain in staggered magnetic…