389 research outputs found
On the Bethe states of the one-dimensional supersymmetric t-J model with generic open boundaries
By combining the algebraic Bethe ansatz and the off-diagonal Bethe ansatz, we
investigate the supersymmetric t-J model with generic open boundaries. The
eigenvalues of the transfer matrix are given in terms of an inhomogeneous T-Q
relation, and the corresponding eigenstates are expressed in terms of nested
Bethe states which have well-defined homogeneous limit. This exact solution
provides basis for further analyzing the thermodynamic properties and
correlation functions of the model.Comment: 17 pages, 2 tables, published versio
Maximized string order parameters in the valence bond solid states of quantum integer spin chains
We propose a set of maximized string order parameters to describe the hidden
topological order in the valence bond solid states of quantum integer spin-S
chains. These optimized string order parameters involve spin-twist angles
corresponding to rotations around or -axes, suggesting a
hidden symmetry. Our results also suggest that a local
triplet excitation in the valence bond solid states carries a
topological charge measured by these maximized string order parameters.Comment: 5 pages, 1 figur
Bethe states of the trigonometric SU(3) spin chain with generic open boundaries
By combining the algebraic Bethe ansatz and the off-diagonal Bethe ansatz, we
investigate the trigonometric SU(3) model with generic open boundaries. The
eigenvalues of the transfer matrix are given in terms of an inhomogeneous T-Q
relation, and the corresponding eigenstates are expressed in terms of nested
Bethe-type eigenstates which have well-defined homogeneous limit. This exact
solution provides a basis for further analyzing the thermodynamic properties
and correlation functions of the anisotropic models associated with higher rank
algebras.Comment: 17 pages, 3 tables. arXiv admin note: text overlap with
arXiv:1705.0947
String order and hidden topological symmetry in the SO(2n+1) symmetric matrix product states
We have introduced a class of exactly soluble Hamiltonian with either
SO(2n+1) or SU(2) symmetry, whose ground states are the SO(2n+1) symmetric
matrix product states. The hidden topological order in these states can be
fully identified and characterized by a set of nonlocal string order
parameters. The Hamiltonian possesses a hidden
topological symmetry. The breaking of this hidden symmetry leads to
degenerate ground states with disentangled edge states in an open chain system.
Such matrix product states can be regarded as cluster states, applicable to
measurement-based quantum computation.Comment: 5 pages, 1 figur
Eliminating interactions between non-neighboring qubits in the preparation of cluster states in quantum molecules
We propose a scheme to eliminate the effect of non-nearest-neighbor qubits in
preparing cluster state with double-dot molecules. As the interaction
Hamiltonians between qubits are Ising-model and mutually commute, we can get
positive and negative effective interactions between qubits to cancel the
effect of non-nearest-neighbor qubits by properly changing the electron charge
states of each quantum dot molecule. The total time for the present multi-step
cluster state preparation scheme is only doubled for one-dimensional qubit
chain and tripled for two-dimensional qubit array comparing with the time of
previous protocol leaving out the non-nearest-neighbor interactions.Comment: 5 pages, 4 figures, 2 table
Class of exactly solvable SO(n) symmetric spin chains with matrix product ground states
We introduce a class of exactly solvable SO(n) symmetric Hamiltonians with
matrix product ground states. For an odd case, the ground state is a
translational invariant Haldane gap spin liquid state; while for an even case, the ground state is a spontaneously dimerized state with twofold
degeneracy. In the matrix product ground states for both cases, we identify a
hidden antiferromagnetic order, which is characterized by nonlocal string order
parameters. The ground-state phase diagram of a generalized SO(n) symmetric
bilinear-biquadratic model is discussed.Comment: 11 pages, 5 figure
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