The effective Lagrangian for Nambu-Goldstone bosons (NGBs) in systems without Lorentz
invariance has a novel feature that some of the NGBs are canonically conjugate to each …

We study an asymmetric J 1-J 2 zigzag ladder consisting of two different spin-1 2
antiferromagnetic (AFM; J 2, γ J 2> 0) Heisenberg legs coupled by zigzag-shaped …

The ground state of the spin-1/2 Heisenberg antiferromagnet on a distorted triangular lattice
is studied using a numerical-diagonalization method. The network of interactions is the type; …

Thermal fluctuations in magnetizations and magnetic phase diagrams of a diatomic
molecule are investigated on the Bethe lattice (BL) with coordination number\(q= 3\) by …

The bulk electric polarization works as a nonlocal order parameter that characterizes
topological quantum matters. Motivated by a recent paper [H. Watanabe, Phys. Rev. B 103 …

Spin nematic phase is a phase of frustrated quantum magnets with a quadrupolar order of
electron spins. Since the spin nematic order is usually masked in experimentally accessible …

We use density-matrix renormalization group to study the first-order quantum phase
transition induced by a magnetic field h in a frustrated ferrimagnetic chain. The …

We compare the ground-state features of alternating ferrimagnetic chains (1/2, S) with S= 1,
3/2, 2, 5/2 in a magnetic field and the corresponding Holstein-Primakoff bosonic models up …

Zero-point quantum fluctuations of a Néel order can produce effective interactions between
quasi-orphan spins weakly coupled to the lattice. On the 3× 3-distorted triangular lattice, this …

Spontaneous symmetry breaking is deeply related to the dimensionality of a system. The
Néel order going with spontaneous breaking of U (1) symmetry is safely allowed at any …