25 citations · 28 across the 3 of their papers we have counts for
5 papers · 1 filter
A Ferromagnetic Lieb-Mattis Theorem
Bruno Nachtergaele, Shannon Starr
We prove ferromagnetic ordering of energy levels for XXX Heisenberg chains of any spin and XXZ spin chains with all spins equal to 1/2. Ferromagnetic ordering means that the minimu…
On the dynamics of interfaces in the ferromagnetic XXZ chain under weak perturbations
Bruno Nachtergaele, Wolfgang L Spitzer, Shannon Starr
We study the time evolution of interfaces of the ferromagnetic XXZ chain in a magnetic field. A scaling limit is introduced where the strength of the magnetic field tends to zero a…
The spectral gap for the ferromagnetic spin-J XXZ chain
Tohru Koma, Bruno Nachtergaele, Shannon Starr
We investigate the spectrum above the kink ground states of the spin J ferromagnetic XXZ chain. Our main theorem is that there is a non-vanishing gap above all ground states of thi…
Some properties for the low-lying spectrum of the ferromagnetic, quantum XXZ spin system
Shannon Starr
In this thesis we present three results about the ferromagnetic quantum XXZ model: 1) Existence of a spectral gap above all infinite-volume ground states in one dimension for any c…
A continuum approximation for the excitations of the (1,1,...,1) interface in the quantum Heisenberg model
Oscar Bolina, Pierluigi Contucci, Bruno Nachtergaele +1
It is shown that, with an appropriate scaling, the energy of low-lying excitations of the (1,1,...,1) interface in the -dimensional quantum Heisenberg model are given by the spe…