Ground state energy and scaling behaviour of spin gap in the XXZ antiferromagnetic chain in longitudinal staggered field

Paul, Susobhan; Ghosh, Asim Kumar

doi:10.1016/j.jmmm.2014.03.035

Cited by 6 publications

(1 citation statement)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Hamiltonian (17) has been studied with different techniques, but mostly for isotropic exchange (γ = 0) or for the easy-plane case (γ < 1), where the interaction and the magnetic field compete [37][38][39][40]. In the present case (γ > 1) the staggered field and the interaction reinforce each other in producing long-range antiferromagnetic order, with up-spins predominantly on even sites and downspins mostly on odd sites.…”

Section: B Small and Large U Limitsmentioning

confidence: 99%

Mass-imbalanced ionic Hubbard chain

et al. 2017

View full text Add to dashboard Cite

A repulsive Hubbard model with both spin-asymmetric hopping (t ↑ = t ↓ ) and a staggered potential (of strength ) is studied in one dimension. The model is a compound of the mass-imbalanced (t ↑ = t ↓ , = 0) and ionic (t ↑ = t ↓ , > 0) Hubbard models, and may be realized by cold atoms in engineered optical lattices. We use mostly mean-field theory to determine the phases and phase transitions in the ground state for a half-filled band (one particle per site). We find that a period-two modulation of the particle (or charge) density and an alternating spin density coexist for arbitrary Hubbard interaction strength, U 0. The amplitude of the charge modulation is largest at U = 0, decreases with increasing U and tends to zero for U → ∞. The amplitude for spin alternation increases with U and tends to saturation for U → ∞. Charge order dominates below a value U c , whereas magnetic order dominates above. The mean-field Hamiltonian has two gap parameters, ↑ and ↓ , which have to be determined self-consistently. For U < U c both parameters are positive, for U > U c they have different signs, and for U = U c one gap parameter jumps from a positive to a negative value. The weakly first-order phase transition at U c can be interpreted in terms of an avoided criticality (or metallicity). The system is reluctant to restore a symmetry that has been broken explicitly.

show abstract

Section: B Small and Large U Limitsmentioning

confidence: 99%

Mass-imbalanced ionic Hubbard chain

et al. 2017

View full text Add to dashboard Cite

show abstract

Variational model for one-dimensional quantum magnets

Kudasov

Kozabaranov

2018

Physics Letters A

View full text Add to dashboard Cite

A new variational technique for investigation of the ground state and correlation functions in 1D quantum magnets is proposed. A spin Hamiltonian is reduced to a fermionic representation by the Jordan-Wigner transformation. The ground state is described by a new non-local trial wave function, and the total energy is calculated in an analytic form as a function of two variational parameters. This approach is demonstrated with an example of the XXZ-chain of spin-1/2 under a staggered magnetic field. Generalizations and applications of the variational technique for low-dimensional magnetic systems are discussed.

show abstract

Scaling behavior of spin gap of the bond alternating anisotropic spin-1/2 Heisenberg chain

Paul¹,

Ghosh²

2016

AIP Conference Proceedings

View full text Add to dashboard Cite

Ground state energy and scaling behaviour of spin gap in the XXZ antiferromagnetic chain in longitudinal staggered field

Cited by 6 publications

References 30 publications

Mass-imbalanced ionic Hubbard chain

Mass-imbalanced ionic Hubbard chain

Variational model for one-dimensional quantum magnets

Scaling behavior of spin gap of the bond alternating anisotropic spin-1/2 Heisenberg chain

Contact Info

Product

Resources

About